CVE-2026-42563: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in jelmer dulwich
Dulwich, a pure-Python Git implementation, contains an OS command injection vulnerability in its ProcessMergeDriver component. Versions from 0.24.0 up to but not including 1.2.5 allow an attacker to execute arbitrary commands by crafting malicious file paths in a branch that a victim merges. This occurs because the file path is substituted into a shell command using subprocess.run with shell=True. The issue is fixed starting in version 1.2.5.
AI Analysis
Technical Summary
The vulnerability in Dulwich arises from improper neutralization of special elements in OS commands (CWE-78). Specifically, the ProcessMergeDriver substitutes the file path from the git tree into the merge driver command via the %P placeholder and executes it with subprocess.run(..., shell=True). Since the file path is attacker-controllable via a malicious branch, this leads to OS command injection when a victim merges such a branch. The vulnerability affects versions starting at 0.24.0 and prior to 1.2.5. Version 1.2.5 addresses this issue.
Potential Impact
An attacker capable of causing a victim to merge a crafted malicious branch can achieve arbitrary command execution on the victim's system. This can lead to full compromise of the affected environment where Dulwich is used to perform merges. The CVSS 4.0 score is 7.7 (high), reflecting network attack vector, low attack complexity, required user interaction, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Version 1.2.5 of Dulwich fixes this vulnerability. Users should upgrade to version 1.2.5 or later to remediate the issue. No official patch or temporary workaround details are provided in the advisory, so upgrading is the recommended action. Patch status is not explicitly confirmed beyond the version fix; users should verify with the vendor advisory for the latest remediation guidance.
CVE-2026-42563: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in jelmer dulwich
Description
Dulwich, a pure-Python Git implementation, contains an OS command injection vulnerability in its ProcessMergeDriver component. Versions from 0.24.0 up to but not including 1.2.5 allow an attacker to execute arbitrary commands by crafting malicious file paths in a branch that a victim merges. This occurs because the file path is substituted into a shell command using subprocess.run with shell=True. The issue is fixed starting in version 1.2.5.
CVSS v4.0
Score 7.7high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Dulwich arises from improper neutralization of special elements in OS commands (CWE-78). Specifically, the ProcessMergeDriver substitutes the file path from the git tree into the merge driver command via the %P placeholder and executes it with subprocess.run(..., shell=True). Since the file path is attacker-controllable via a malicious branch, this leads to OS command injection when a victim merges such a branch. The vulnerability affects versions starting at 0.24.0 and prior to 1.2.5. Version 1.2.5 addresses this issue.
Potential Impact
An attacker capable of causing a victim to merge a crafted malicious branch can achieve arbitrary command execution on the victim's system. This can lead to full compromise of the affected environment where Dulwich is used to perform merges. The CVSS 4.0 score is 7.7 (high), reflecting network attack vector, low attack complexity, required user interaction, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Version 1.2.5 of Dulwich fixes this vulnerability. Users should upgrade to version 1.2.5 or later to remediate the issue. No official patch or temporary workaround details are provided in the advisory, so upgrading is the recommended action. Patch status is not explicitly confirmed beyond the version fix; users should verify with the vendor advisory for the latest remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-28T17:26:12.083Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a29e5e331875706499a3982
Added to database: 06/10/2026, 22:32:03 UTC
Last enriched: 06/18/2026, 18:00:29 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 71
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