---
id: "CVE-2026-128036"
page: "https://infrastack.ai/live/CVE-2026-128036"
kind: "vulnerability"
aliases: ["CVE-2026-128036"]
title: "gittuf: policy update skips signature checks on rule files"
severity: "low"
cvss: 2.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["git", "gittuf", "package", "supply-chain"]
not_affected_if: ["gittuf-not-used", "version-outside-range"]
published_at: "2026-11-13T16:18:58+00:00"
first_seen_at: "2026-11-13T16:47:33+00:00"
updated_at: "2026-11-13T16:49:00+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-128036", "first_seen_at": "2026-11-13T16:47:33+00:00"}]
exploit_sources: []
---

# gittuf: policy update skips signature checks on rule files

Link for people: https://infrastack.ai/live/CVE-2026-128036 (this .md is for agents)

gittuf, a Git security tool, verifies only the root-of-trust signatures on a new policy and not the signatures on its rule files. A user already trusted to push to the repository can craft an invalid policy that verification accepts, which changes the rules for later changes.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed gittuf version with `gittuf --version` and see whether it falls in 0.4.0 through 0.16.0.
- Look for a policy update in the reference state log of repositories that use gittuf verification.

## Fix

- Move to a gittuf release newer than 0.16.0 (the fixed version is not named in the sources given; see the release notes).

## Timeline

- 2026-11-13T16:47:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-128036

## Documents

- [advisory] Vendor advisory: github.com https://github.com/gittuf/gittuf/security/advisories/GHSA-774m-m728-236h
- [fix] Release notes: github.com https://github.com/gittuf/gittuf/releases/tag/v0.17.0

## From the sources

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.

---

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