Bug 2570304 (CVE-2026-123806)

Summary: CVE-2026-123806 tuf: python-tuf: Unauthorized update delivery via case-insensitive path matching on Windows
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: eborisov, lball, ngough, veshanka
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in python-tuf. On Windows systems, delegation path pattern matching is performed case-insensitively due to platform-specific path normalization. In repositories with delegation patterns that differ only by letter case, an attacker controlling a delegated role can provide target files intended for a different role. Consequently, affected clients on Windows may accept unauthorized or malicious software updates.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-11-10 19:49:32 UTC 
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.