CVE-2026-47712
Dulwich doesn't sanitize commit subjects in `porcelain.format_patch`
Description
Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.24.0 and prior to version 1.2.5, dulwich.porcelain.format_patch(outdir=...) derives each patch filename from the commit's subject line. Prior to this fix, get_summary only replaced spaces with dashes - path separators (/, \), parent-directory components (..), and other filename-hostile characters (e.g. :) were preserved verbatim and passed straight into os.path.join(outdir, f"{i:04d}-{summary}.patch"). A malicious commit subject could therefore direct the generated patch file outside the requested outdir. This is fixed in Dulwich 1.2.5. Users should upgrade to 1.2.5 or later. dulwich.patch.get_summary now mirrors git's format_sanitized_subject: only `[A-Za-z0-9._]` are kept, runs of other characters collapse to a single -, consecutive . collapse to a single ., trailing ./- are stripped, and the result is length-limited. This makes the returned string safe to embed as a filename component, so format_patch can no longer be steered out of outdir via the commit subject. Until upgrading, callers that pass untrusted commits to porcelain.format_patch can use stdout=True and write the patch to a destination they control, rather than letting format_patch choose the filename; validate the chosen path before opening - e.g. compare os.path.realpath(returned_path) against os.path.realpath(outdir) and reject any patch whose resolved path is not inside outdir; and/or pre-screen commits and refuse to format any whose subject's first line contains /, \, .., or other characters that are not safe on the target filesystem.
INFO
Published Date :
June 10, 2026, 11:16 p.m.
Last Modified :
July 21, 2026, 7:10 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Upgrade Dulwich to version 1.2.5 or later.
- Sanitize commit subject lines to remove path separators.
- Validate patch file paths before writing to disk.
- Use stdout=True for untrusted commits if upgrading is not possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-47712.
| URL | Resource |
|---|---|
| https://github.com/jelmer/dulwich/commit/c2446e51b | |
| https://github.com/jelmer/dulwich/releases/tag/dulwich-1.2.5 | |
| https://github.com/jelmer/dulwich/security/advisories/GHSA-555p-6grf-mh7f |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-47712 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-47712
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-47712 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-47712 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Jul. 21, 2026
Action Type Old Value New Value Added Translation Title: Dulwich de jelmer, Description: Dulwich es una implementación puramente en Python de los formatos de archivo y protocolos de Git. A partir de la versión 0.24.0 y antes de la versión 1.2.5, dulwich.porcelain.format_patch(outdir=...) deriva cada nombre de archivo de parche de la línea de asunto del commit. Antes de esta corrección, get_summary solo reemplazaba los espacios con guiones - los separadores de ruta (/, \), los componentes de directorio padre (..), y otros caracteres hostiles para nombres de archivo (p. ej. :) se conservaban textualmente y se pasaban directamente a os.path.join(outdir, f"{i:04d}-{summary}.patch"). Un asunto de commit malicioso podría, por lo tanto, dirigir el archivo de parche generado fuera del outdir solicitado. Esto se corrige en Dulwich 1.2.5. Los usuarios deberían actualizar a la versión 1.2.5 o posterior. dulwich.patch.get_summary ahora refleja el format_sanitized_subject de git: solo se mantienen '[A-Za-z0-9._]', las secuencias de otros caracteres se colapsan a un solo -, los puntos consecutivos se colapsan a un solo ., los ./- finales se eliminan, y el resultado tiene una longitud limitada. Esto hace que la cadena devuelta sea segura para incrustar como un componente de nombre de archivo, por lo que format_patch ya no puede ser dirigido fuera de outdir a través del asunto del commit. Hasta que se actualice, los llamadores que pasan commits no confiables a porcelain.format_patch pueden usar stdout=True y escribir el parche en un destino que controlen, en lugar de dejar que format_patch elija el nombre de archivo; validar la ruta elegida antes de abrir - p. ej. comparar os.path.realpath(returned_path) con os.path.realpath(outdir) y rechazar cualquier parche cuya ruta resuelta no esté dentro de outdir; y/o pre-filtrar commits y negarse a formatear cualquiera cuya primera línea del asunto contenga /, \, .., u otros caracteres que no sean seguros en el sistema de archivos de destino. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'jelmer', 'product': 'dulwich', 'versions': [{'status': 'affected', 'version': '>= 0.24.0, < 1.2.5'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-47712', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-11T12:41:02.775185Z'} -
New CVE Received by [email protected]
Jun. 10, 2026
Action Type Old Value New Value Added Description Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.24.0 and prior to version 1.2.5, dulwich.porcelain.format_patch(outdir=...) derives each patch filename from the commit's subject line. Prior to this fix, get_summary only replaced spaces with dashes - path separators (/, \), parent-directory components (..), and other filename-hostile characters (e.g. :) were preserved verbatim and passed straight into os.path.join(outdir, f"{i:04d}-{summary}.patch"). A malicious commit subject could therefore direct the generated patch file outside the requested outdir. This is fixed in Dulwich 1.2.5. Users should upgrade to 1.2.5 or later. dulwich.patch.get_summary now mirrors git's format_sanitized_subject: only `[A-Za-z0-9._]` are kept, runs of other characters collapse to a single -, consecutive . collapse to a single ., trailing ./- are stripped, and the result is length-limited. This makes the returned string safe to embed as a filename component, so format_patch can no longer be steered out of outdir via the commit subject. Until upgrading, callers that pass untrusted commits to porcelain.format_patch can use stdout=True and write the patch to a destination they control, rather than letting format_patch choose the filename; validate the chosen path before opening - e.g. compare os.path.realpath(returned_path) against os.path.realpath(outdir) and reject any patch whose resolved path is not inside outdir; and/or pre-screen commits and refuse to format any whose subject's first line contains /, \, .., or other characters that are not safe on the target filesystem. Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N Added CWE CWE-22 Added Reference https://github.com/jelmer/dulwich/commit/c2446e51b Added Reference https://github.com/jelmer/dulwich/releases/tag/dulwich-1.2.5 Added Reference https://github.com/jelmer/dulwich/security/advisories/GHSA-555p-6grf-mh7f