CVE-2026-42305

/// Technical description

Dulwich is a pure-Python implementation of the Git file formats and protocols. Versions starting with 0.10.0 and prior to 1.2.5 have an arbitrary file write leading to remote code execution when cloning or checking out a malicious Git repository on Windows. Dulwich's path-element validator accepted tree entries whose filenames contained bytes that Windows interprets as structural path syntax. Contributing configuration bugs made matters worse. The core.protectNTFS and core.protectHFS settings were looked up under a wrong option name and so user-set values were silently ignored, and core.protectNTFS only defaulted to true on Windows (Git upstream has defaulted it to true everywhere since CVE-2019-1353). Both have been corrected. Anyone who clones, fetches, or checks out an untrusted repository with Dulwich on Windows - either through the Dulwich CLI, porcelain.clone, or any downstream tool built on Dulwich - is impacted. POSIX clones are not directly exploitable (on POSIX \ is a literal

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References