# CVE-2026-114094: Dulwich path traversal via DOS drive letter prefixes on Windows

Source: https://junglewise.ai/threats/cve-2026-114094-dulwich-before-1-2-9-fails-to-validate-dos-drive-letter-prefixes  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-114094 · Severity: high · CVSS 8.8 · Published 2026-10-21

Dulwich is a Python Git implementation library used to clone and manage repositories. On Windows systems, a malicious Git repository can be crafted to write files outside the intended directory by bypassing path validation, leading to arbitrary file write and remote code execution. This could compromise CI/CD runners, steal SSH keys, or plant malware when a Windows user clones an untrusted repository.

Technologies: [Jelmer Dulwich](https://junglewise.ai/threats/technologies/jelmer-dulwich). Vendors: [Jelmer](https://junglewise.ai/threats/vendors/jelmer).

## Quick answers

**Is CVE-2026-114094 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-114094 being exploited in the wild.

**How severe is CVE-2026-114094?** High severity, with a CVSS score of 8.8, published 21 October 2026.

**Which products and versions are affected?** Jelmer Dulwich before 1.2.9.

**Is there a fix for CVE-2026-114094?** Yes: fixed in 1.2.9. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-114094 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-114094?** Check whether you run Jelmer Dulwich 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

- Fixed in 1.2.9

## Technical details

A path traversal vulnerability exists in Dulwich's NTFS path validation functions (validate_path_element_ntfs, _tree_to_fs_path) which fail to block DOS drive letter prefixes like "C:" in Git tree entries. When checkout occurs on Windows, os.path.join() treats a second argument starting with a drive letter as absolute, discarding the repository root path and writing files to arbitrary system locations. The vulnerability requires a user to clone a malicious repository but allows pre-authentication exploitation.

## Affected products

- Jelmer Dulwich before 1.2.9

## Timeline

- 2026-07-06: disclosed
- 2026-10-21: advisory

## References

- [https://github.com/jelmer/dulwich/security/advisories/GHSA-8mcx-5rqc-vhmf](https://github.com/jelmer/dulwich/security/advisories/GHSA-8mcx-5rqc-vhmf)
- [https://www.vulncheck.com/advisories/dulwich-before-1.2.9-arbitrary-file-write-via-dos-drive-letter-paths](https://www.vulncheck.com/advisories/dulwich-before-1.2.9-arbitrary-file-write-via-dos-drive-letter-paths)

## Related threats

- [Dulwich commit object parsing divergence from git](https://junglewise.ai/threats/cve-2026-122299-dulwich-before-1-2-20-contains-a-commit-object-parsing)
- [Dulwich path traversal in stash pop via symlinks](https://junglewise.ai/threats/cve-2026-114098-dulwich-from-0-22-5-before-1-2-8-contains-a-path-traversal)
- [Dulwich path traversal in filter_branch CommitFilter](https://junglewise.ai/threats/cve-2026-114097-dulwich-from-0-23-1-before-1-2-8-contains-a-path-traversal)
- [Dulwich symlink following in porcelain.checkout](https://junglewise.ai/threats/cve-2026-114096-dulwich-from-0-24-0-before-1-2-8-contains-a-symlink-following)