# CVE-2026-47191: Siemens kas improper verification of git commit IDs

Source: https://junglewise.ai/threats/cve-2026-47191-siemens-kas-improper-verification-of-git-commit-ids  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-01. Updated: 2026-06-01  
License: CC BY 4.0 with a link back

CVE-2026-47191 · Severity: medium · CVSS 4 · Published 2026-06-01

Siemens kas is a tool used to set up and build complex software projects by managing multiple source code repositories. A vulnerability exists where the tool can be tricked into downloading a malicious version of source code if an attacker creates a branch name that looks like a specific version identifier (a git commit hash). This could allow an attacker who has compromised a source repository to execute a supply-chain attack by providing unauthorized code instead of the expected version.

Technologies: [kas (PyPI)](https://junglewise.ai/threats/technologies/kas). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-47191 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47191 being exploited in the wild.

**How severe is CVE-2026-47191?** Medium severity, with a CVSS score of 4, published 1 June 2026.

**Which products and versions are affected?** kas (PyPI) < 5.3, ECOSYSTEM:introduced=0,fixed=5.3.

**Is there a fix for CVE-2026-47191?** Yes. kas (PyPI): upgrade to 5.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-47191 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-47191?** Check whether you run kas (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- kas (PyPI): upgrade to 5.3 or later

  ```sh
  pip install "kas>=5.3"
  ```


## Technical details

A vulnerability in Siemens kas (prior to version 5.3) allows for the substitution of a git commit with a branch of the same name. When kas performs a checkout using a commit ID (SHA-1 or SHA-256) for integrity validation, it does not explicitly force the reference to be treated as a commit object. An attacker who has gained control over a referenced repository can create a branch named with the hex string of a valid commit hash. Because git checkout prioritizes or accepts branch names that match the hash string, kas may check out the head of the malicious branch instead of the specific immutable commit. This issue is mitigated by appending '^{commit}' to the reference during checkout to ensure only commit objects are resolved.

## Affected products

- Siemens kas < 5.3

## Identifiers

- CVE-2026-47191
- GHSA-qjwp-hrq6-r26r
- PYSEC-2026-2544

## Timeline

- 2026-05-27: disclosed: Initial publication by Siemens
- 2026-06-01: advisory: GitHub Advisory published
- 2026-06-01: patched: Released in version 5.3

## References

- [https://github.com/siemens/kas/security/advisories/GHSA-qjwp-hrq6-r26r](https://github.com/siemens/kas/security/advisories/GHSA-qjwp-hrq6-r26r)
- [https://github.com/siemens/kas/commit/4cb4a3d01122ffaec9feaae768a5814092f6f9b5](https://github.com/siemens/kas/commit/4cb4a3d01122ffaec9feaae768a5814092f6f9b5)
- [https://api.github.com/repos/siemens/kas/security-advisories/GHSA-qjwp-hrq6-r26r](https://api.github.com/repos/siemens/kas/security-advisories/GHSA-qjwp-hrq6-r26r)

## Related threats

- [Siemens kas SSH host key checking configuration weakness](https://junglewise.ai/threats/cve-2026-54548-siemens-kas-ssh-host-key-checking-configuration-weakness)
- [Siemens kas improper signature verification in repository processing](https://junglewise.ai/threats/cve-2026-47192-siemens-kas-improper-signature-verification-in-repository)