CVE-2026-42305
published 2026-06-10CVE-2026-42305: 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…
PriorityP354high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.64%
48.1th percentile
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.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| ansible-automation-platform-26 | controller-rhel9 | — | — |
| ansible-automation-platform-27 | controller-rhel9 | — | — |
| dulwich_project | dulwich | >= 0.10.0 < 1.2.5 | 1.2.5 |
| rhoai | odh-kserve-autogluon-server-rhel9 | — | — |
| rhoai | odh-kserve-storage-initializer-rhel9 | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
ghsa9.8CRITICAL
vendor_redhat9.8CRITICAL
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GHSA
Dulwich has an arbitrary file write via NTFS-hostile tree entries on Windows
ghsa·2026-05-28·CVSS 9.8
CVE-2026-42305 [CRITICAL] CWE-22 Dulwich has an arbitrary file write via NTFS-hostile tree entries on Windows
Dulwich has an arbitrary file write via NTFS-hostile tree entries on Windows
## Impact
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:
- \ — the Windows path separator. A single tree entry named .git\hooks\pre-commit.exe was treated as one valid filename on POSIX but materialized as nested directories .git/hooks/pre-commit.exe on Windows, planting a file inside the victim's .git directory. Git for Windows then
executes that hook on the next git commit, giving the attacker arbitrary code execution in the victim's user context. The same primitive can be used with ..\outside.txt t
Red Hat
dulwich: Dulwich: Remote Code Execution via Malicious Git Repository
vendor_redhat·2026-06-10·CVSS 9.8
CVE-2026-42305 [CRITICAL] CWE-22 dulwich: Dulwich: Remote Code Execution via Malicious Git Repository
dulwich: Dulwich: Remote Code Execution via Malicious Git Repository
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 cor
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-42305 python-dulwich: Dulwich: Remote Code Execution via Malicious Git Repository [epel-all]
bugzilla·2026-07-09·CVSS 9.8
CVE-2026-42305 [CRITICAL] CVE-2026-42305 python-dulwich: Dulwich: Remote Code Execution via Malicious Git Repository [epel-all]
CVE-2026-42305 python-dulwich: Dulwich: Remote Code Execution via Malicious Git Repository [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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
Bugzilla
CVE-2026-42305 python-dulwich: Dulwich: Remote Code Execution via Malicious Git Repository [fedora-all]
bugzilla·2026-07-09·CVSS 9.8
CVE-2026-42305 [CRITICAL] CVE-2026-42305 python-dulwich: Dulwich: Remote Code Execution via Malicious Git Repository [fedora-all]
CVE-2026-42305 python-dulwich: Dulwich: Remote Code Execution via Malicious Git Repository [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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 a
Bugzilla
CVE-2026-42305 dulwich: Dulwich: Remote Code Execution via Malicious Git Repository
bugzilla·2026-06-10·CVSS 9.8
CVE-2026-42305 [CRITICAL] CVE-2026-42305 dulwich: Dulwich: Remote Code Execution via Malicious Git Repository
CVE-2026-42305 dulwich: Dulwich: Remote Code Execution via Malicious Git Repository
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). Bot
2026-06-10
Published