CVE-2026-128036: Low severity gittuf gittuf vulnerability
In gittuf 0.4.0 through 0.16.0, when a policy update appears within the range of reference state log entries being verified, verification checks only the root of trust signatures of the new policy and not the signatures of its other metadata (rule files). A user trusted to push to the repository who bypasses gittuf policy apply and writes the policy reference and reference state log directly can make an invalid policy apply during verification, weakening or strengthening the rules for later changes. The update is still recorded in the reference state log.
Affected Software
Event History
Frequently Asked Questions
Who can realistically exploit this issue?
An attacker must already be trusted to push to the repository and must be able to bypass gittuf policy apply by writing the policy reference and reference state log directly. This is not described as exploitable by an unauthenticated or read-only repository user.
What conditions make verification vulnerable?
The issue occurs when a policy update appears within the range of reference state log entries being verified. In that situation, verification checks signatures on the new policy's root of trust but does not verify signatures on its other metadata, including rule files.
What could an attacker accomplish?
A qualifying attacker can cause an invalid policy to apply during verification, allowing rules governing later changes to be weakened or strengthened. The malicious update remains recorded in the reference state log.
What versions should be remediated?
The affected versions are gittuf 0.4.0 through 0.16.0. The provided release reference identifies v0.17.0 as the relevant release.