sequoia-git has broken hard revocation handling

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

1.8 · CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Before sq-git checks if a commit can be authenticated, it first looks for hard revocations. Because parsing a policy is expensive and a project's policy rarely changes, sq-git has an optimization to only check a policy if it hasn't checked it before. It does this by maintaining a set of policies that it had already seen keyed on the policy's hash. Unfortunately, due to a bug the hash was truncated to be 0 bytes and thus only hard revocations in the target commit were considered. Normally this is not a problem as hard revocations are not removed from the signing policy. An attacker could nevertheless exploit this flaw as follows. Consider Alice and Bob who maintain a project together. If Bob's certificate is compromised and Bob issues a hard revocation, Alice can add it to the project's signing policy. An attacker who has access to Bob's key can then create a merge request that strips the hard revocation. If Alice merges Bob's merge request, then the latest commit will not carry the…

Published by the source

4 May 2026, 22:28 UTC

Last modified by the source

4 May 2026, 22:28 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-g27r-r6ph-vf5r

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-g27r-r6ph-vf5r

Advisory: sequoia-git has broken hard revocation handling
IDs: GHSA-g27r-r6ph-vf5r
Record: https://patchnext.com/advisories/ghsa-g27r-r6ph-vf5r (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 1.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sequoia-git 0.6.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io sequoia-git: affected < 0.6.0; fixed in 0.6.0

## Suggested inspection (read-only)
- crates.io sequoia-git: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sequoia-git.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-g27r-r6ph-vf5r (GitHub-reviewed advisory GHSA-g27r-r6ph-vf5r lists affected ranges: crates.io sequoia-git >=0 <0.6.0)

Commands are suggestions: review each one before running it.