---
id: CVE-2026-114094
title: Dulwich before 1.2.9 Arbitrary File Write via DOS drive letter paths
summary: >-
  Dulwich before 1.2.9 fails to validate DOS drive letter prefixes in Git tree
  path elements on Windows, allowing arbitrary file write. Attackers can craft a
  malicious repository with a tree entry named 'C:' that bypasses NTFS
  validation a…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-22
vendor: jelmer
product: dulwich
affected:
  - dulwich < 1.2.9
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T00:36:58.401Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114094'
references:
  - url: 'https://github.com/jelmer/dulwich/security/advisories/GHSA-8mcx-5rqc-vhmf'
    label: GitHub Security Advisory (GHSA-8mcx-5rqc-vhmf)
  - url: >-
      https://www.vulncheck.com/advisories/dulwich-before-1.2.9-arbitrary-file-write-via-dos-drive-letter-paths
    label: >-
      VulnCheck Advisory: Dulwich before 1.2.9 Arbitrary File Write via DOS
      drive letter paths
tags:
  - cve.org
ingestedAt: '2026-10-21T01:37:08.019Z'
---

## Overview

Dulwich before 1.2.9 fails to validate DOS drive letter prefixes in Git tree path elements on Windows, allowing arbitrary file write. Attackers can craft a malicious repository with a tree entry named 'C:' that bypasses NTFS validation and writes files outside the worktree to achieve remote code execution.

## Affected

- `dulwich < 1.2.9`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.