# CVE-2026-123806: python-tuf: Platform-dependent delegation path matching

Status: published. Published: 2026-11-09. Updated: 2026-11-09.

python-tuf is a Python reference implementation of The Update Framework (TUF). Prior to 7.0.0, DelegatedRole._is_target_in_pathpattern in tuf/api/_payload.py uses fnmatch.fnmatch, which applies os.path.normcase before matching and makes delegation path authorization case-insensitive on Windows. When a TUF repository has path-based delegations that differ only by case and an attacker-controlled role is visited before the legitimate role, ngclient can accept an attacker-provided target from the wrong delegation for a requested path. Linux and macOS clients are not affected because their path normalization does not change case. This issue is fixed in 7.0.0.

## Remediation

- fix: tuf (PyPI): OSV reports a fixed version 7.0.0. Check the advisory for supported release branches. (source: OSV GHSA-qp9x-wp8f-qgjj) — https://github.com/advisories/GHSA-qp9x-wp8f-qgjj

## Affected products and versions

- theupdateframework / python-tuf: < 7.0.0 (affected). Source: CNA: GitHub_M
-  / tuf (tuf): 0.10.0 (affected, PyPI); 0.10.1 (affected, PyPI); 0.10.2 (affected, PyPI); 0.11.0 (affected, PyPI); 0.11.1 (affected, PyPI); 0.11.2.dev1 (affected, PyPI); 0.11.2.dev2 (affected, PyPI); 0.11.2.dev3 (affected, PyPI); 0.11.dev0 (affected, PyPI); 0.12.0 (affected, PyPI); 0.12.1 (affected, PyPI); 0.12.2 (affected, PyPI); 0.12.dev0 (affected, PyPI); 0.12.dev1 (affected, PyPI); 0.12.dev2 (affected, PyPI); 0.13.0 (affected, PyPI); 0.14.0 (affected, PyPI); 0.15.0 (affected, PyPI); 0.16.0 (affected, PyPI); 0.17.0 (affected, PyPI); 0.18.0 (affected, PyPI); 0.18.1 (affected, PyPI); 0.19.0 (affected, PyPI); 0.20.0 (affected, PyPI); 0.7.5 (affected, PyPI); 0.9.8 (affected, PyPI); 0.9.9 (affected, PyPI); 1.0.0 (affected, PyPI); 1.1.0 (affected, PyPI); 2.0.0 (affected, PyPI); 2.1.0 (affected, PyPI); 3.0.0 (affected, PyPI); 3.1.0 (affected, PyPI); 3.1.1 (affected, PyPI); 4.0.0 (affected, PyPI); 5.0.0 (affected, PyPI); 5.1.0 (affected, PyPI); 6.0.0 (affected, PyPI); Ecosystem version events: introduced 0; fixed 7.0.0. Source: OSV GHSA-qp9x-wp8f-qgjj

## Severity and prioritization

- CVSS 3.1: 4 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-178

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/theupdateframework/python-tuf/security/advisories/GHSA-qp9x-wp8f-qgjj (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/theupdateframework/python-tuf/commit/8ed4414946041030b264871ac41b929cf15774a5 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/theupdateframework/python-tuf/releases/tag/v7.0.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/advisories/GHSA-qp9x-wp8f-qgjj (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-qp9x-wp8f-qgjj (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-123806; retrieved 2026-11-09; source updated 2026-11-09

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-qp9x-wp8f-qgjj; retrieved 2026-11-09; source updated 2026-11-09

Revision: 9788afcdd95d3510d8f2b3b8e3f64a34dc6dd50cdca234554ac0618e0ff8de49

Canonical: https://y2.dev/cve/CVE-2026-123806

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