CVE-2026-123806

MEDIUM 4.0

python-tuf: Platform-dependent delegation path matching

CVSS Score

4.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-178
Vendor	theupdateframework
Product	python-tuf
Published	Nov 9, 2026

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CVSS v3 Breakdown

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Affected Versions

theupdateframework / python-tuf

< 7.0.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/theupdateframework/python-tuf/security/advisories/GHSA-qp9x-wp8f-qgjj github.com: https://github.com/theupdateframework/python-tuf/commit/8ed4414946041030b264871ac41b929cf15774a5 github.com: https://github.com/theupdateframework/python-tuf/releases/tag/v7.0.0