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CVE-2026-47712

CVE-2026-47712 · Dulwich doesn't sanitize commit subjects in `porcelain.format_patch`

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 3.3 · Low · EPSS 0.2% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • dulwich

    Versions
    • >= 0.24.0, < 1.2.5: Affected

    No fix published

  • dulwich Debian:12

    Versions
    • 0.21.2-1
    • 0.21.5-1
    • 0.21.6-1
    • 0.22.5-1
    • 0.22.7-1
    • 0.22.7-2
    • 0.24.10-1
    • 0.24.2-1
    • 0.24.2-2
    • 1.0.0-1
    • 1.0.0-2
    • 1.1.0-1
    • 1.1.0-2
    • 1.1.0-3
    • 1.2.0-1
    • 1.2.1-1
    • 1.2.11-1
    • 1.2.12-1
    • 1.2.5-1
    • 1.2.7-1
    • 1.2.7-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Debian:13

    Versions
    • 0.22.7-1
    • 0.22.7-2
    • 0.24.10-1
    • 0.24.2-1
    • 0.24.2-2
    • 1.0.0-1
    • 1.0.0-2
    • 1.1.0-1
    • 1.1.0-2
    • 1.1.0-3
    • 1.2.0-1
    • 1.2.1-1
    • 1.2.11-1
    • 1.2.12-1
    • 1.2.5-1
    • 1.2.7-1
    • 1.2.7-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Debian:14

    Versions
    • 0.22.7-1
    • 0.22.7-2
    • 0.24.10-1
    • 0.24.2-1
    • 0.24.2-2
    • 1.0.0-1
    • 1.0.0-2
    • 1.1.0-1
    • 1.1.0-2
    • 1.1.0-3
    • 1.2.0-1
    • 1.2.1-1
    Affected ranges
    • ECOSYSTEM: < 1.2.5-1

    Update to 1.2.5-1

  • dulwich PyPI

    Versions
    • 0.24.0
    • 0.24.1
    • 0.24.10
    • 0.24.2
    • 0.24.3
    • 0.24.4
    • 0.24.5
    • 0.24.6
    • 0.24.7
    • 0.24.8
    • 0.24.9
    • 0.25.0
    • 0.25.1
    • 0.25.2
    • 1.0.0
    • 1.1.0
    • 1.2.0
    • 1.2.1
    • 1.2.2
    • 1.2.3
    • 1.2.4
    Affected ranges
    • ECOSYSTEM: ≥ 0.24.0, < 1.2.5

    Update to 1.2.5

  • dulwich Ubuntu:16.04:LTS

    Versions
    • 0.11.2-1ubuntu1
    • 0.12.0-1
    • 0.12.0-1build1
    • 0.12.0-1build2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:18.04:LTS

    Versions
    • 0.18.2-1build1
    • 0.18.5-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:20.04:LTS

    Versions
    • 0.19.11-2
    • 0.19.14-4ubuntu1
    • 0.19.15-1
    • 0.19.15-1build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:22.04:LTS

    Versions
    • 0.20.15-1ubuntu1
    • 0.20.31-1ubuntu1
    • 0.20.31-1.1
    • 0.20.31-1.1build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:24.04:LTS

    Versions
    • 0.21.6-1
    • 0.21.6-1build1
    • 0.21.6-1build2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:25.10

    Versions
    • 0.22.7-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:26.10

    Versions
    • 1.1.0-3
    • 1.2.12-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dulwich Ubuntu:26.04:LTS

    Versions
    • 0.22.7-1
    • 0.24.2-2
    • 1.1.0-2ubuntu1
    • 1.1.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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