CVE-2026-73621: GitPython before 3.1.56 Arbitrary File Truncation via Commit.count

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-08-13 · updated 2026-10-24
Weakness: CWE-88

Description

GitPython before 3.1.56 contains an argument injection vulnerability in the Commit.count() method, which forwards keyword arguments to 'git rev-list' without the check_unsafe_options guard present in the sibling iter_items method. An attacker who can control options passed to Commit.count (e.g., via an application that forwards a user-supplied options dict) can supply output=<path>, causing 'git rev-list --output=<path>' to open and truncate the target file to zero bytes before revision parsing. This allows destruction/blanking of an arbitrary file at the process's privilege level (no content control, 0-byte truncation).

Affected products

gitpython-developers GitPython: before 3.1.56 — fixed in 3.1.56

How to fix

Upgrade to a fixed version: gitpython-developers GitPython 3.1.56. Check the vendor advisory for mitigations.

References

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