GHSA-QJWP-HRQ6-R26R
Vulnerability from github – Published: 2026-06-01 14:26 – Updated: 2026-06-01 14:26Impact
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": [
{
"package": {
"ecosystem": "PyPI",
"name": "kas"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "5.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-47191"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-01T14:26:36Z",
"nvd_published_at": null,
"severity": "LOW"
},
"details": "### Impact\nWhen 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.\n\n### Patches\nCommit https://github.com/siemens/kas/commit/4cb4a3d01122ffaec9feaae768a5814092f6f9b5 is resolving this issue. It has been released along with kas version 5.3.\n\n### Workarounds\nAvoid 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.\n\n### Credits\nThat 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\u0027t 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.",
"id": "GHSA-qjwp-hrq6-r26r",
"modified": "2026-06-01T14:26:36Z",
"published": "2026-06-01T14:26:36Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/siemens/kas/security/advisories/GHSA-qjwp-hrq6-r26r"
},
{
"type": "WEB",
"url": "https://github.com/siemens/kas/commit/4cb4a3d01122ffaec9feaae768a5814092f6f9b5"
},
{
"type": "PACKAGE",
"url": "https://github.com/siemens/kas"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "kas checks out SHA-like git branches as valid commits"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.