GHSA-9r75-g2cr-3h76

Source

https://github.com/advisories/GHSA-9r75-g2cr-3h76

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-9r75-g2cr-3h76/GHSA-9r75-g2cr-3h76.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-9r75-g2cr-3h76

Published

2026-03-06T18:45:02Z

Modified

2026-03-06T19:02:20.219400Z

Severity

5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator

Summary

Vercel Workflow Allows Webhook Creation with Predictable User-Specified Tokens

Details

createWebhook() in Vercel Workflow DevKit accepts a user-specified token parameter that serves as the credential for the public webhook endpoint /.well-known/workflow/v1/webhook/{token}. Official documentation recommended predictable token patterns, making it possible for an unauthenticated remote attacker to guess the token and inject arbitrary payloads into the workflow execution context.

Impact

An attacker who guesses a webhook token can resume the associated workflow with an attacker-controlled HTTP request body, potentially triggering downstream side effects such as API calls, database writes, or deployments.

Fix

Upgrade to version 4.2.0-beta.64. The fix removes the token option from createWebhook() so that webhook tokens are always randomly generated by the SDK.
Runs created with versions prior to 4.2.0-beta.64, that are 1) still active (i.e. running), and 2) have open hooks, are still susceptible to this vulnerability. If users suspect the hook tokens are predictable or leaked - consider cancelling those runs and restarting them on the latest patch.

Workarounds

In case a version upgrade is not possible, avoid passing predictable or guessable values to the token parameter of createWebhook(). Instead, users can either

switch from createWebhook() to createHook() instead and programmatically resume hooks using resumeHook() instead of the public webhook endpoint, or
use createWebhook() without passing a user-provided token, which uses a non-guessable random nanoid by default.

Database specific

{
    "github_reviewed": true,
    "cwe_ids": [
        "CWE-287"
    ],
    "nvd_published_at": null,
    "github_reviewed_at": "2026-03-06T18:45:02Z",
    "severity": "MODERATE"
}

References

Affected packages

npm / workflow

Package

Name: workflow; View open source insights on deps.dev
Purl: pkg:npm/workflow

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

4.2.0-beta.64

Database specific

last_known_affected_version_range

"<= 4.1.0-beta.63"

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-9r75-g2cr-3h76/GHSA-9r75-g2cr-3h76.json"

npm / @workflow/core

Package

Name: @workflow/core; View open source insights on deps.dev
Purl: pkg:npm/%40workflow/core

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

4.2.0-beta.64

Database specific

last_known_affected_version_range

"<= 4.1.0-beta.63"

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-9r75-g2cr-3h76/GHSA-9r75-g2cr-3h76.json"