{"id":"PYSEC-2026-3950","details":"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=\u003cpath\u003e, causing 'git rev-list --output=\u003cpath\u003e' 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).","aliases":["CVE-2026-73621","GHSA-p538-c434-8v24"],"modified":"2026-09-10T13:00:03.065349275Z","published":"2026-08-13T12:17:27.200Z","references":[{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/gitpython-before-arbitrary-file-truncation-via-commit-count"},{"type":"EVIDENCE","url":"https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-p538-c434-8v24"}],"affected":[{"package":{"name":"gitpython","ecosystem":"PyPI","purl":"pkg:pypi/gitpython"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1.56"}]}],"versions":["0.1.7","0.2.0-beta1","0.3.0-beta1","0.3.0-beta2","0.3.1-beta2","0.3.2","0.3.2.1","0.3.2.RC1","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","1.0.0","1.0.1","1.0.2","2.0.0","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.7","2.0.8","2.0.9","2.0.9.dev0","2.0.9.dev1","2.1.0","2.1.1","2.1.10","2.1.11","2.1.12","2.1.13","2.1.14","2.1.15","2.1.2","2.1.3","2.1.4","2.1.5","2.1.6","2.1.7","2.1.8","2.1.9","3.0.0","3.0.1","3.0.2","3.0.3","3.0.4","3.0.5","3.0.6","3.0.7","3.0.8","3.0.9","3.1.0","3.1.1","3.1.10","3.1.11","3.1.12","3.1.13","3.1.14","3.1.15","3.1.16","3.1.17","3.1.18","3.1.19","3.1.2","3.1.20","3.1.22","3.1.23","3.1.24","3.1.25","3.1.26","3.1.27","3.1.28","3.1.29","3.1.3","3.1.30","3.1.31","3.1.32","3.1.33","3.1.34","3.1.35","3.1.36","3.1.37","3.1.38","3.1.4","3.1.40","3.1.41","3.1.42","3.1.43","3.1.44","3.1.45","3.1.46","3.1.47","3.1.48","3.1.49","3.1.5","3.1.50","3.1.51","3.1.52","3.1.53","3.1.54","3.1.55","3.1.6","3.1.7","3.1.8","3.1.9"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/gitpython/PYSEC-2026-3950.yaml"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}