The Vercel breach: OAuth attack exposes risk in platform environment variables

Posted by queenelvis 6 hours ago

Vercel April 2026 security incident - https://news.ycombinator.com/item?id=47824463 - April 2026 (485 comments)

A Roblox cheat and one AI tool brought down Vercel's platform - https://news.ycombinator.com/item?id=47844431 - April 2026 (145 comments)

Comments

Comment by westont5 5 hours ago

I'm not sure I've seen it mentioned yet that when Vercel rolled out their environment variable UI, there was no "sensitive" option https://github.com/vercel/vercel/discussions/4558#discussion.... There was ~2 years or more until it was introduced https://vercel.com/changelog/sensitive-environment-variables...

Comment by nopointttt 1 hour ago

A sensitive flag at the UI layer doesn't actually change runtime. Once it's in process.env during a build, any dep that decides to grep it can. The real problem isn't a missing checkbox, it's that we still stuff every secret into one env bag and hand the build tools the whole bag. Cloudflare scoped bindings and Fly already split it up, other platforms are just slower.

Comment by _pdp_ 5 hours ago

Sensitive does not mean it is not readable. It is just simply not exposed through the UI. It can be easily leaked if you return a bit too much props from the action functions or routes.

The only way to defend against these types of issues is to encrypt your environment with your own keys, with secrets possibly baked into source as there are no other facilities to separate them. An attacker would need to not only read the environments but also download the compiled functions and find the decryption keys.

It is not ideal but it could work as a workaround.

Comment by harikb 4 hours ago

> with secrets possibly baked into source

please don't suggest this. The right way is to have the creds fetched from a vault, which is programmed to release the creds auth-free to your VM (with machine level identify managed by the parent platform)

This is how Google Secrets or AWS Vaults work.

Comment by chatmasta 3 hours ago

Next.js renders configuration that’s shared by client and server into a JSON blob in the HTML page. These config variables often come from environment variables. It’s a very common mistake for people to not realize this, and accidentally put what should be a server-only secret into this config. I’ve seen API secrets in HTML source code because of this. The client app doesn’t even use it, but it’s part of the next config so it renders into the page.

Comment by whh 2 hours ago

That's essentially what NEXT_PUBLIC_ is for... but serializing process.env is a new one for me.

Comment by chatmasta 2 hours ago

They don’t serialize process.env, but devs will take config values from environment variables. Obviously you’re not supposed to do this but it’s a footgun.

Comment by socalgal2 2 hours ago

IIRC, react had this issue so they required env vars seen in react to be prefixed by REACT_ The hope being that SECRET is not prefixed and so is not available. Of course it requires you to know why they are prefixed and not make REACT_SECRET

Comment by jcgl 4 hours ago

> The right way is to have the creds fetched from a vault, which is programmed to release the creds auth-free to your VM

Or have whatever deployment tool that currently populates the env vars instead use the same information to populate files on the filesystem (like mounting creds).

Comment by _pdp_ 4 hours ago

I was reffering to Vercel. Other cloud environments have much better mechanisms for securing secrets.

Comment by SoftTalker 4 hours ago

This is just another layer of indirection (which isn't bad; it adds to the difficulty of executing a breach). The fundamental problem with encrypted secrets is that at some point you need to access and decrypt them.

Comment by zbentley 1 hour ago

I'm not sure that's necessarily a "problem", though it is fundamental to secrets. We wouldn't say that it's a fundamental problem that doors on houses need a key--that's what the key is for--the problem is if the key isn't kept secure from unauthorized actors.

Like, sure, you can go HAM here and use network proxy services to do secret decryption, and only talk from the app to those proxies via short-lived tokens; that's arguably a qualitative shift from app-uses-secret-directly, and it has some real benefits (and costs, namely significant complexity/fragility).

Instead, my favored option is to scope secret use to network locations. If, for example, a given NPM token can only be used for API calls issued from the public IP endpoint of the user's infrastructure, that's a significant added layer of security. People don't agree on whether or not this counts as a "token ACL", but it's certainly ACL-like in its functionality--just controlled by location, rather than identity.

This approach can also be adopted gradually and with less added fragility than the proxy-all-the-things approach: token holders can initially allowlist broad or shared network location ranges, and narrow allowed access sources over time as their networks are improved.

Of course, that's a fantasy. API providers would have to support network-scoped API access credentials, and almost none of them do.

Comment by socketcluster 32 minutes ago

Yep. Then you run into the issue of where to store the secret encryption key.

Security researchers always need to give an answer whenever there's a security incident and the answer can never be "too much centralization risk" even when that is the only reasonable answer. You can't remove centralization risk.

IMO, the future is; every major centralized platform will be insecure in perpetuity and nothing can be done about it.

Comment by SAI_Peregrinus 4 hours ago

HSMs & similar can at least time-limit access to secrets to the period where an attacker can make requests to the HSM.

Comment by recursivegirth 3 hours ago

I think the problem is the way we are using these "secrets" services traditionally. The requesting process/machine should NEVER see the Oauth client secret. The short-lived session token should be the only piece of data the server/client are ever privy too.

The service that encrypts the data should be the ONLY service that holds the private key to decrypt, and therefore the only service that can process the decrypted data.

Comment by oasisbob 3 hours ago

The service wouldn't have access to the refresh token? How does authentication with the client-secret-holding intermediary work?

It's easy to see how this would work with sufficiently sophisticated clients in some use-cases, say via a vault plugin, but posing this as a universal necessity feels like a big departure from typical oauth flows, and the added complexity could be harmful depending on what home-grown solutions are used to implement it.

Comment by 2 hours ago

Comment by awestroke 4 hours ago

The better way to defend against these types of issues is to avoid Vercel and similar providers

Comment by 5 hours ago

Comment by tosser12344321 2 hours ago

There are going to be a lot more like this as the IT-enabled economy at large catch up to the risk debt of broad-based experimentation with AI tools from large and small vendors.

It's "AI-enabled tradecraft" as in let's take a guess at Vercel leadership's pressure to install and test AI across the company, regardless of vendor risk? Speed speed speed.

This is an extremely vanilla exploit that every company operating without a strictly enforceable AI install allowlist is exposed to - how many AI tools like Context are installed across your scope of local and SaaS AI? Odds are, quite a bit, or ask your IT guy/gal for estimates.

These tools have access to... everything! And with a security vendor and RBAC mechanism space that'll exist in about... 18-24 months.

Vercel is the canary. It's going to get interesting here, no way in heck that Context is the only target. This is a well established, well-concerned/well-ignored threat vector, when one breaks open the other start too.

Implies a very challenging 6 months ahead if these exploits are kicking off, as everyone is auditing their AI installs now (or should be), and TAs will fire off with the access they have before it is cut.

Source - am a head of sec in tech

Comment by thundergolfer 4 hours ago

> AI-accelerated tradecraft. The CEO publicly attributed the attacker's unusual velocity to AI augmentation — an early, high-profile data point in the 2026 discourse around AI-accelerated adversary tradecraft.

Attributed without evidence from what I could tell. So it doesn't reveal much at all.

Comment by 12_throw_away 3 hours ago

Seems like AI is really disrupting the markets for nonsensical excuses the media will repeat uncritically!

Comment by mday27 2 hours ago

It's like we're back in 2009 with "did social media cause this?"

Comment by tom1337 5 hours ago

I still don't get how this exactly worked. Is the OAuth Token they talk about the one that you get when a user uses "Sign in with Google"? Aren't they then bound to the client id and client secret of that specific Google App the user signed in to? How were the attackers able to go from that to a control plane? Because even if the attacker knows the users OAuth token, the client id and the client secret, they can access the Google Drive etc. (which is bad, I get that) but I simply do not understand how they could log in into any Vercel systems from that point. Did they find the credentials in the google drive?

Comment by gizzlon 2 hours ago

They don't really say. My guess would be something embarrassing, and that's why they are keeping it to themselves. Maybe passwords in Drive og Gmail. Or just passwordless login links (like sibling said)

Comment by _pdp_ 5 hours ago

Once you have a session token, which is what you get after you complete the oauth dance, you can issue requests to the API. It is simple as that. The minted token had permission to access the victim's inbox, most likely, which the attacker leveraged to read email and obtain one-time passwords, magic links and other forms of juicy information.

Comment by progbits 3 hours ago

If they had SSO sign in to their admin panel (trusted device checks notwithstanding) the oauth access would be useless.

Vercel is understandably trying to shift all the blame on the third party but the fact their admin panel can be accessed with gmail/drive/whatever oauth scopes is irresponsible.

Comment by zbentley 1 hour ago

That's a low-leverage place to intervene. Whether or not the internal admin system was directly OAuth linked to Google, by the time the attacker was trying that, they already had a ton of sensitive/valuable info from the employee's Google Workspace account.

If you can only fix one thing (ideally you'd do both, but working in infosec has taught me that you can usually do one thing at most before the breach urgency political capital evaporates), fix the Google token scope/expiry, or fix the environment variable storage system.

Comment by kyle-rb 2 hours ago

I guess what's unusual is that the scope includes inbox access.

IMO it's probably a bad idea to have an LLM/agent managing your email inbox. Even if it's readonly and the LLM behaves perfectly, supply chain attacks have an especially large blast radius (even more so if it's your work email).

Comment by TeMPOraL 1 hour ago

It's a bit of a pickle, given that managing your inbox (or at least reading it, classifying and summarizing contents, identifying action items etc.) is one of the most valuable applications of LLMs today, especially if you move beyond software developers having LLMs write code for them.

Comment by chatmasta 2 hours ago

I’m not clear on it either. Was the Context.ai OAuth application compromised? So the threat actor essentially had the same visibility into every Context.ai customer’s workspace that Context.ai has? And why is a single employee being blamed? Did this Vercel employee authorize Context.ai to read the whole Vercel workspace?

Comment by datadrivenangel 5 hours ago

"Effective defense requires architectural change: treating OAuth apps as third‑party vendors, eliminating long‑lived platform secrets, and designing for the assumption of provider‑side compromise."

Designing for provider-side compromise is very hard because that's the whole point of trust...

Comment by losvedir 5 hours ago

As someone trying to think about OAuth apps at our SaaS, it certainly is very hard.

Do any marketplaces have a good approach here? I know Cloudflare, after their similar Salesloft issue, has proposed proxying all 3rd party OAuth and API traffic through them. But that feels a little bit like trading one threat vector for another.

Other than standard good practices like narrow scopes, shorter expirations, maybe OAuth Client secret rotation, etc, I'm not sure what else can be done. Maybe allowlisting IP addresses that the requests associated with a given client can come from?

Comment by mooreds 5 hours ago

This was probably partly a Google refresh token theft (given the length of the access). No inside info, just looking at how the attack occurred.

OAuth 2.1[0] (an RFC that has been around longer than I've been at my employer) recommends some protections around refresh tokens, either making them sender constrained (tied to the client application by public/private key cryptography) or one-time use with revocation if it is used multiple times.

This is recommended for public clients, but I think makes sense for all clients.

The first option is more difficult to implement, but is similar to the IP address solution you suggest. More robust though.

The second option would have made this attack more difficult because the refresh token held by the legit client, context.ai, would have stopped working, presumably triggering someone to look into why and wonder if the tokens had been stolen.

0: https://datatracker.ietf.org/doc/html/draft-ietf-oauth-v2-1

Comment by hvb2 3 hours ago

One time use of refresh tokens is really common? Where each refresh will get you a new access token AND a new refresh token?

That's standard in oidc I believe

Comment by mooreds 3 hours ago

I don't have data on whether it is common, but I know a few OAuth vendors support it.

Comment by wouldbecouldbe 5 hours ago

I mean the admin account had visibility of clients env vars, thats maybe not really great in the first place.

Comment by iririririr 4 hours ago

you'd think. but this is a js dev world.

nextjs app bake all env vars on the client side code!! it's all public, unless you prefix the name with private_ or something.

Comment by rozenmd 3 hours ago

This is incorrect.

You preface with PUBLIC_ to expose them in client side code.

Comment by nyc_data_geek1 5 hours ago

Corroborates that zero-trust until now has been largely marketing gibberish. Security by design means incorporating concepts such as these to not assume that your upstream providers will not be utterly owned in a supply chain attack.

Comment by _pdp_ 5 hours ago

> OAuth trust relationship cascaded into a platform-wide exposure

> The CEO publicly attributed the attacker's unusual velocity to AI

> questions about detection-to-disclosure latency in platform breaches

Typical! The main failures in my mind are:

1. A user account with far too much privileges - possible many others like them

2. No or limited 2FA or any form of ZeroTrust architecture

3. Bad cyber security hygiene

Comment by JauntyHatAngle 5 hours ago

Blaming AI is gonna be the security breach equivalent to blaming ddos when your website breaks isn't it.

Comment by progbits 2 hours ago

It's the new sophisticated nation state.

Comment by anematode 4 hours ago

That part of his tweet made me laugh out loud. I don't understand who it's directed toward.

Comment by BoorishBears 4 hours ago

The market. Rauch is 'strategic' like that, he'd even use a moment like this sneak in a sound bite to froth the market he has so much skin in

"Vercel CEO says AI accelerated attack on critical infrastructure"

Comment by anematode 3 hours ago

sigh Right.

Ironically, if the timeline is true that the attackers had been inside for months, the AIs they had access to are substantially weaker than today's frontier models. How much faster would they have achieved their goals with GLM 5.1?

Comment by xienze 3 hours ago

I think there’s a lot of truth to “the AI did it” though. We’re encouraging the same people who get tricked by “attached is your invoice” emails to run agent harnesses that have control of your desktop. I think there’s gonna be a lot of AI-powered exploits in the future.

Comment by oasisbob 2 hours ago

Some of the details in this report, like the timeline beginning in 2024-2025, haven't been widely reported?

Anyone know where these dates are being sourced from? eg,

> Late 2024 – Early 2025: Attacker pivots from Context.ai OAuth access to a Vercel employee's Google Workspace account -- CONFIRMED — Rauch statement

> Early - mid-2025: Internal Vercel systems accessed; customer environment variable enumeration begins -- CONFIRMED — Vercel bulletin

Comment by captn3m0 1 hour ago

These are all made up and likely hallucinated.

Comment by saadn92 5 hours ago

What bites people: rotating a vercel env variable doesn't invalidate old deployments, because previous deploys keep running with the old credential until you redeploy or delete them. So if you rotated your keys after the bulletin but didn't redeploy everything, then the compromised value is still live.

Also worth checking your Google Workspace OAuth authorizations. Admin Console > Security > API Controls > Third-party app access. Guarantee there are apps in there you authorized for a demo two years ago that are still sitting with full email/drive access.

Comment by quentindanjou 5 hours ago

Usually rotating a credential means that you invalidate the previous one. Never heard of rotating credentials that would only create new ones and keep the old ones active.

Comment by simlevesque 4 hours ago

But then every rotation would break production, wouldn't it ?

Comment by cortesoft 3 hours ago

rotations are usually two phased. Add new secret/credential to endpoint, and both new and old are active and valid. Release new secret/credential to clients of that endpoint, and wait until you dont see any requests using the old credential.

Then you remove the old credential from the endpoint.

Comment by kstrauser 4 hours ago

Ideally, you can have a couple of working versions at any given time. For instance, an AWS IAM role can have 0 to 2 access keys configured at once. To rotate them, you deactivate all but one key, create a new key, and make that new key the new production value. Once everything's using that key, you can deactivate the old one.

Comment by oasisbob 2 hours ago

> What bites people: rotating a vercel env variable doesn't invalidate old deployments, because previous deploys keep running with the old credential until you redeploy or delete them. So if you rotated your keys after the bulletin but didn't redeploy everything, then the compromised value is still live.

That statement in the report really confuses me; feels illogical and LLM generated.

An old deployment using an older env var doesn't do anything to control whether or not the credential is still valid. This is a footgun which affects availability, not confidentiality like implied.

Another section in the report is confusing, "Environment variable enumeration (Stage 4)". The described mechanics of env var access are bizarre to me -

> Pay particular attention to any environment variable access originating from user accounts rather than service accounts, or from accounts that do not normally interact with the projects being accessed.

Are people really reading credentials out of vercel env vars for use in other systems?

Comment by wouldbecouldbe 5 hours ago

When you rotate them, you supposed expire your old vars

Comment by kevinqi 4 hours ago

yeah not redeploying on credential changes seems like a design flaw. Render redeploys on env var changes, for instance.

Comment by treexs 3 hours ago

Vercel very clearly highlights that you need to redeploy once you make a credential change

Comment by hungryhobbit 4 hours ago

Why is this same story repeated over and over here?

I get it, it's a big story ... but that doesn't mean it needs N different articles describing the same thing (where N > 1).

Comment by jackconsidine 4 hours ago

New information here -- I had no idea that Env enumeration was happening MONTHS before the disclosure for example and that's part of why I come to HN.

Would guess that double digit percent of readers have some level of skin in the game with Vercel

Comment by thisisauserid 3 hours ago

Maybe this flood is a response to the constant flood of:

"Why do people use Vercel?"

"Because it's cheap* and easy."

*expensive

Comment by The_Blade 3 hours ago

i didn't know it was OAuth related. when did that hit the front page here?

in fact, the sparse details had Barbara warming up her vocal chords

Comment by pier25 3 hours ago

Funny how the headline tries to spin this as an env vars issue.

By far the biggest issue is being able to access the production environment of millions of customers from a Google Workspace. Only a handful of Vercel employees should be able to do that with 2FA if not 3FA.

Comment by jwpapi 3 hours ago

No one should be, why are the enverionmant variables not encrypted itself and the encryption key is stored with your oauth provider ?

Comment by progbits 2 hours ago

Vercel runtime must be able to access the values (so customer's apps can use them). But nobody else should ever be able to. This is the typical amateur hour security but on the other hand, who was naive enough to expect any better from vercel?

Comment by ubershmekel 2 hours ago

I'm building something that isn't necessarily more secure than vercel, but it is self hosted. I think in the future personal vps family clouds are going to be a lot more common because of these cloud-level attacks and costs.

Comment by greenmilk 4 hours ago

To me the biggest (but not only) issue is that blindly connecting sensitive tools to 3rd party services has been normalized. Every time I hear the word "claw" I cringe...

Comment by jwpapi 3 hours ago

What are these non-sensitive variables that could only be the NEXT_PUBLIC ones? else I haven’t seen any difference?

Or is it the UI sensitive that they ask you in CLI, that would be crazy. That means if you decide to not mark them as sensitive they don’t store encrypted ???

Comment by donglong 3 hours ago

those are environment variables that the frontend can consume, hence the public prefix

Comment by krooj 5 hours ago

Interesting - I wonder if this isn't a case of theft on a refresh token that was minted by a non-confidential 3LO flow w/PKCE. That would explain how a leaked refresh token could then be used to obtain access, but does the Vercel A/S not implement any refresh token reuse detection? i.e.: you see the same R/T more than once, you nuke the entire session b/c it's assumed the R/T was compromised.

Comment by pier25 4 hours ago

> The CEO publicly attributed the attacker's unusual velocity to AI

Unusual velocity? Didn't the attacker have the oauth keys for months?

Comment by steve1977 3 hours ago

But they got it via Context.ai, so there you have it, it's even in the name!

Comment by jdiaz97 3 hours ago

He's just lying tbh, this sounds cool and makes you sound less incompetent

Comment by 5 hours ago

Comment by 6 hours ago

Comment by throwaway27448 5 hours ago

Do any services use vercel?

Comment by drusepth 5 hours ago

It's a really common platform for vibe coded sites, as I understand it.

Comment by raw_anon_1111 2 hours ago

I used v0 for a vibe coded internal admin app.

*BUT* I downloaded the source code from Vercel’s site, built and deployed in a Docker container (I never download random npm packages to my local computer), deployed the Docker container to Lambda (choose your Docker deployment platform. They are a dime a dozen), had a tightly scoped IAM role attached to the Lambda and my secrets were in Secret Manager.

My deployment also had a placeholder for the secrets when it was deployed and they were never in my repo and purposefully had to be manually configured.

I would never trust something like Vercel for hosting. I’m not saying go all in on a major cloud provider. Get your own cheap VPS if that’s all you need and take responsibility for your own security posture the best you can.

Comment by jdw64 5 hours ago

First of all, it is often used in Korea.

Comment by antonvs 5 hours ago

Small startups often use it but typically outgrow it quickly unless they remain small and simple.

Comment by vaguemit 6 hours ago

I recently went to BreachForums and the space was filled with this

Comment by 5 hours ago

Comment by akanet 4 hours ago

This article is solely overly wordy (probably ai) restatements of essentially just what vercel has publicly disclosed already

Comment by phoenixranger 3 hours ago

sad of state of all shorts of media lately

Comment by semiquaver 4 hours ago

I’m sure this has been said before but the new part of me is that the initial breach happened 22 months ago and has been sitting undetected that whole time. This really looks quite bad for vercel’s security posture.

Comment by forrestthewoods 1 hour ago

I hate environment variables. I hate them so so so much. I can’t think of a single time I would prefer an envvar to a config file.

They’re somewhat necessary when dealing with Docker. But I also hate Docker. So it’s not surprising when one bad design pattern leads to another.

I suppose maybe envvars make sense when dealing with secrets? I’m not sure. I don’t do any webdev. So not sure what’s least bad solution there.

Comment by pphysch 5 hours ago

Security-by-obfuscation is ridiculed but I'm a firm believer that preventing yourself from getting owned when someone is able to type 3 letters `env` is a worthy layer of defense. Even if those same secrets are unencrypted somewhere else on the same system, at least make them spend a bunch of time crawling through files and such.

Comment by Quarrelsome 5 hours ago

It's ridiculed because its no protection on its own when an attacker is motivated. Its fine to add as an additional layer though if you want to make your space mildly custom to protect against broader attacks.

I don't see how its necessarily relevant to this attack though. These guys were storing creds in clear and assuming actors within their network were "safe", weren't they?

Comment by pphysch 5 hours ago

TFA cites "env var enumeration", likely implying someone got somewhere they shouldn't and typed 3 characters, as the critical attack that led to customers getting compromised.

My point is sensitive secrets should literally never be exported into the process environment, they should be pulled directly into application memory from a file or secrets manager.

It would still be a bad compromise either way, but you have a fighting chance of limiting the blast radius if you aren't serving secrets to attackers on an env platter, which could be the first three characters they type once establishing access.

Comment by kstrauser 4 hours ago

The following is based on my interpretation of information that's been made public:

A Vercel user had their Google Workspace compromised.

The attacker used the compromised workspace to connect to Vercel, via Vercel's Google sign-on option.

The attacker, properly logged into the Vercel console as an employee of that company, looked at the company's projects' settings and peeked at the environment variables section, which lists a series of key:value pairs.

The user's company had not marked the relevant environment variables as "sensitive", which would have hidden their values from the logged-in attacker. Instead of

  DATABASE_PASSWORD: abcd_1234 [click here to update]

it would have shown:

  DATABASE_PASSWORD: ****** [click here to update]

with no way to reveal the previously stored value.

And that's how the attacker enumerated the env vars. They didn't have to compromise a running instance or anything. They used their improperly acquired but valid credentials to log in as a user and look at settings that user had access to.

Comment by dboreham 3 hours ago

Astonishing that high damage actions were authorized by authentication delegated to Google and furthermore not subject to hard token 2FA.

Comment by lbarrow 5 hours ago

I don't think that's what the attacker did here. Vercel is a PaaS product where other developers run apps. The enumerated environment variables were the env vars of Vercel's customers, which Vercel likely stores in a long-term data store. Rather than running `env` on a Linux box somewhere, the attacker may have just accessed that data store.