GHSA-892p-pqrr-hxqr

Source

https://github.com/advisories/GHSA-892p-pqrr-hxqr

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/05/GHSA-892p-pqrr-hxqr/GHSA-892p-pqrr-hxqr.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-892p-pqrr-hxqr

Aliases

CVE-2025-46332

Published

2025-05-02T19:28:40Z

Modified

2025-05-02T19:57:14.024114Z

Severity

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

Summary

Information Disclosure via Flags override link

Details

Summary

An information disclosure vulnerability affecting Flags SDK has been addressed. It impacted flags ≤3.2.0 and @vercel/flags ≤3.1.1 and in certain circumstances, allowed a bad actor with detailed knowledge of the vulnerability to list all flags returned by the flags discovery endpoint (.well-known/vercel/flags).

Impact

This vulnerability allowed for information disclosure, where a bad actor could gain access to a list of all feature flags exposed through the flags discovery endpoint, including the:

Flag names
Flag descriptions
Available options and their labels (e.g. true, false)
Default flag values

Not impacted:

Flags providers were not accessible

No write access nor additional customer data was exposed, this is limited to just the values noted above. Vercel has automatically mitigated this incident on behalf of our customers for the default flags discovery endpoint at .well-known/vercel/flags. Flags Explorer will be disabled and show a warning notice until upgraded to flags@4.0.0.

Resolution

The verifyAccess function was patched within flags@4.0.0.

Users of @vercel/flags should also migrate to flags@4.0.0.

For further guidance on upgrading your version, please see our upgrade guide.

Mitigations

Vercel implemented a network-level mitigation to prevent the default flags discovery endpoint at /.well-known/vercel/flags being reachable, which automatically protects Vercel deployments against exploitation of this issue. Users need to upgrade to flags@4.0.0 to re-enable the Flags Explorer.

This automatic mitigation is not effective in two scenarios:

When using the Flags SDK on Pages Router, as the original non-rewritten route would still be accessible, e.g. /api/vercel/flags.
When using a custom path for the flags discovery endpoint.

If you are not protected by the Vercel default mitigation you can temporarily deny access to the other exposed flags discovery endpoints through a custom WAF rule while you upgrade to the latest version.

References

https://vercel.com/changelog/information-disclosure-in-flags-sdk-cve-2025-46332
https://github.com/vercel/flags/blob/main/packages/flags/guides/upgrade-to-v4.md

Database specific

{
    "nvd_published_at": "2025-05-02T17:15:52Z",
    "cwe_ids": [
        "CWE-200"
    ],
    "severity": "MODERATE",
    "github_reviewed": true,
    "github_reviewed_at": "2025-05-02T19:28:40Z"
}

References

Affected packages

npm / flags

Package

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

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

4.0.0

Database specific

{
    "last_known_affected_version_range": "<= 3.2.0"
}

npm / @vercel/flags

Package

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

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Last affected

3.1.1