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 filename byte), but a POSIX user can unknowingly propagate a malicious tree to Windows consumers via push or re-publication. This issue is fixed in Dulwich 1.2.5. Users should upgrade to 1.2.5 or later. There is no effective pre-patch workaround. On affected versions the core.protectNTFS configuration key was silently ignored, so setting it to true does not mitigate the issue. Users who cannot upgrade should avoid cloning, fetching, or checking out untrusted repositories with Dulwich on Windows. After upgrading the NTFS validator is on by default on every platform, so no additional configuration is required.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-fbd55e52fb advisory.

    1.2.9, CVE fixes

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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 filename byte), but a POSIX
    user can unknowingly propagate a malicious tree to Windows consumers via push or re-publication. This
    issue is fixed in Dulwich 1.2.5. Users should upgrade to 1.2.5 or later. There is no effective pre-patch
    workaround. On affected versions the core.protectNTFS configuration key was silently ignored, so setting
    it to true does not mitigate the issue. Users who cannot upgrade should avoid cloning, fetching, or
    checking out untrusted repositories with Dulwich on Windows. After upgrading the NTFS validator is on by
    default on every platform, so no additional configuration is required. (CVE-2026-42305)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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 filename byte), but a POSIX     user can unknowingly propagate a malicious tree to Windows consumers via push or re-publication. This     issue is fixed in Dulwich 1.2.5. Users should upgrade to 1.2.5 or later. There is no effective pre-patch     workaround. On affected versions the core.protectNTFS configuration key was silently ignored, so setting     it to true does not mitigate the issue. Users who cannot upgrade should avoid cloning, fetching, or     checking out untrusted repositories with Dulwich on Windows. After upgrading the NTFS validator is on by     default on every platform, so no additional configuration is required. (CVE-2026-42305)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
326391	Fedora 44 : python-dulwich (2026-fbd55e52fb)	Nessus	Fedora Local Security Checks	high
442450	SCA: security update for dulwich (GHSA-897w-fcg9-f6xj)	Tenable Cloud Security	SCA Checks	high
442450	SCA: security update for dulwich (GHSA-897w-fcg9-f6xj)	Tenable Self-Hosted Container Security	SCA Checks	high
317714	Linux Distros Unpatched Vulnerability : CVE-2026-42305	Nessus	Misc.	high

Detections

Analytics

CVE-2026-42305

high

Tenable Plugins

high

high

high

high