CVE-2026-47191 — kas
Fix: siemens/kas@4cb4a3dCVE-2026-47191 is a CWE-347 vulnerability in kas. A fix is available for kas — see the affected versions and patch details below.
kas checks out SHA-like git branches as valid commits
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-47191.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
kasReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
When relying solely on a git commit ID (SHA-1 or SHA-256) to qualify if a checkout of a repository is equivalent to the state validated while adding its commit ID to a kas configuration, users may be tricked to check out a branch of the same name from this repository. This implies that the referenced repository has been taken over by an attacker and modified to carry such a branch. SHA-1 commits may also be replaced by creating hash collisions, so the primary impact of this issue is on SHA-256 commit IDs.
Patches
Commit https://github.com/siemens/kas/commit/4cb4a3d01122ffaec9feaae768a5814092f6f9b5 is resolving this issue. It has been released along with kas version 5.3.
Workarounds
Avoid relying solely on the commit ID for integrity validation of a repository that might become under control of a malicious 3rd party. If available, additional validate cryptographically signed commits or tags. Alternatively, mirror the repository to a save place, validate its integrity, and use this instead of the original one.
Credits
That such issues exist was already reported 3 years ago by Aditya Sirish A Yelgundhalli. At this point, no strong integrity checks for external repositories were in place in kas, and Siemens stated in the kas documentation that such attacks are considered out of scope. This hasn't changed for SHA-1 commits as explained above. If a repo provides SHA-256 commits, though, those may be considered strong enough (even if not providing authenticity proof) and can be affected by this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | kas | all versions | 5.3pip install --upgrade 'kas==5.3' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for kas, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update kas to 5.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-47191 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-47191 in your dependencies?
Find it across PyPI, including transitive dependencies.