VulnerabilityPublished 10 Jun 2026

CVE-2026-47712: jelmer dulwich · Path Traversal

Affects jelmer dulwichSource CVE Database V5

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Not known to be exploited · CVSS 3.3 Low : upgrade to 1.2.5 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

3.3Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.2.5

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade jelmer dulwich to 1.2.5.

Affected software

Product	Affected	Fixed in
jelmerdulwich	Affected >=0.24.0 <1.2.5	Fixed in 1.2.5
PyPIdulwich`pkg:pypi/dulwich`Other threats	Affected >=0.24.0 <1.2.5	Fixed in 1.2.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should upgrade to Dulwich version 1.2.5 or later where this vulnerability is fixed. Until upgrading, callers processing untrusted commits should use the stdout=True option to avoid automatic filename generation, validate resolved patch file paths to ensure they remain within the intended directory, and/or pre-screen commit subjects to reject those containing unsafe characters such as /, \, or .. in the first line. These mitigations reduce the risk of path traversal until an official fix is applied.

Description

### Impact 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. Reduced examples: - x/../../x produced <outdir>/0001-x/../../x.patch, resolving two directories above outdir. - x\..\..\x produced the equivalent escape on Windows, here \ is also a path separator. Related issues from the same root cause: - Subjects containing characters that are illegal in Windows filenames (e.g. :) caused format_patch to fail outright on Windows, where git would have succeeded. - Very long subjects produced excessively long filenames that could exceed filesystem limits; git truncates them. Anyone calling porcelain.format_patch (or the dulwich format-patch CLI) against untrusted commits - for example, a service that runs format-patch over user-supplied repositories or pull requests - could have patch files written to attacker-chosen locations within the process's write permissions. ### Patches Fixed in Dulwich 1.2.5. Users should upgrade. 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. ### Workarounds 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. - 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. ### Resources - Fix commit: https://github.com/jelmer/dulwich/commit/c2446e51b - Affected API: dulwich.porcelain.format_patch / dulwich format-patch - Reference behavior: git's format_sanitized_subject in pretty.c

Impact

An attacker who can supply commit subjects to dulwich.porcelain.format_patch could cause patch files to be written outside the intended directory, potentially overwriting arbitrary files if the environment permits. The CVSS score is low (3.3) with no confidentiality or availability impact, only limited integrity impact. There are no known exploits in the wild.

Summary

The vulnerability in Dulwich's porcelain.format_patch function arises because patch filenames are derived from commit subject lines without adequately sanitizing path separators, parent-directory components, or other unsafe filename characters. This allows a crafted commit subject to cause patch files to be written outside the specified output directory (path traversal). The flaw affects versions >=0.24.0 and <1.2.5. The fix in 1.2.5 updates dulwich.patch.get_summary to sanitize commit subjects similarly to git's format_sanitized_subject, restricting characters to alphanumerics, dots, and underscores, collapsing runs of unsafe characters, and stripping trailing unsafe characters, thus preventing directory escape via patch filenames.

CWE-22Improper Limitation of a Pathname to a Restricted Directory (Path Traversal) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Jun 2026, 22:46 UTC

WeaknessesCWE-22

Technical details

References

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