tuf has platform-dependent delegation path matching

Exploitation

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

CVSS

4.0 · CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

DelegatedRole.istargetinpathpattern uses fnmatch.fnmatch to decide whether a given target path is authorized by a delegation's glob pattern. Python's fnmatch.fnmatch calls os.path.normcase() on both arguments before matching. On POSIX hosts normcase is the identity function; on Windows hosts os.path resolves to ntpath, whose normcase lowercases its input and replaces / with \. As a result, python-tuf's delegation path pattern matching is case-sensitive on Linux/macOS but case-INSENSITIVE on Windows. This makes the authorization decision for a target dependent on the host operating system of the client running the updater. The result on Windows is a TUF specification violation in the python-tuf ngclient implementation. Vulnerable code tuf/api/payload.py (HEAD 7ecb67d): fnmatch.fnmatch source (Python 3.12, unchanged in current mainline): Fix Replace fnmatch.fnmatch with fnmatch.fnmatchcase, which is explicitly documented as "not applying case normalization", so it behaves identically…

Published by the source

28 May 2026, 22:46 UTC

Last modified by the source

10 Sep 2026, 03:51 UTC

Source last checked

26 Oct 2026, 13:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-qp9x-wp8f-qgjj

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-qp9x-wp8f-qgjj

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# Patch Next advisory brief: GHSA-qp9x-wp8f-qgjj

Advisory: tuf has platform-dependent delegation path matching
IDs: GHSA-qp9x-wp8f-qgjj
Record: https://patchnext.com/advisories/ghsa-qp9x-wp8f-qgjj (revision 2, source checked 26 Oct 2026, 13:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tuf 7.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI tuf: affected <= 6.0.0; fixed in 7.0.0

## Suggested inspection (read-only)
- `python -m pip show tuf`: prints the installed version. Run with the environment that serves production active.

## 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 tuf.
- 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://osv.dev/vulnerability/GHSA-qp9x-wp8f-qgjj (OSV record GHSA-qp9x-wp8f-qgjj lists affected ranges: PyPI tuf >=0 <7.0.0 (fixed))
- Verified: https://github.com/advisories/GHSA-qp9x-wp8f-qgjj (GitHub-reviewed advisory GHSA-qp9x-wp8f-qgjj lists affected ranges: PyPI tuf >=0 <=6.0.0)

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