GitPython: Regular expression denial of service in actor parsing
Summary
GitPython parses author, committer and tagger lines of commit and tag objects with a regular expression that backtracks quadratically when the trailing epoch or timezone is missing or malformed. An attacker who gets an application to read a crafted commit or tag object from an untrusted repository can exhaust CPU, with each access to Commit.author, Commit.committer or TagObject.tagger taking seconds. The attack requires no privileges or user interaction, and the impact is limited to availability.
Affected
- GitPython before 3.2.0 (vendor advisory lists versions 3.1.62 and earlier as affected)
Fixed in
- Upgrade to GitPython 3.2.0 or later
Workaround
- No vendor workaround known. Unknown whether other mitigations exist beyond upgrading.
- Interim measure: do not let CI runners or scanners clone or inspect untrusted repositories until the upgrade is done.
Exploitation
- CISA SSVC: exploitation status poc, automatable yes, technical impact partial.
- Not listed in CISA KEV.
- No evidence of in-the-wild exploitation found.
- A public proof of concept exists in the GitHub advisory.
Our recommendation
- Upgrade GitPython to 3.2.0 or later wherever it is present, including transitive dependencies (for example via dvc or scmrepo).
- Check lockfiles and container images for affected versions.
- Limit which repositories CI pipelines and scanners process until patched.
- Monitor CPU usage of build agents and scanners for unusual load.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-m64x-33q8-m5h7 github.com
- VulnCheck advisory www.vulncheck.com
- OSV GHSA-m64x-33q8-m5h7 osv.dev
- GitLab advisory mirror advisories.gitlab.com
- Ubuntu CVE-2026-110856 ubuntu.com
- OpenCVE CVE-2026-110856 app.opencve.io
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 02:43.
Original description (NVD)
GitPython before 3.2.0 contains a regular expression denial of service vulnerability in the _re_actor_epoch pattern used by parse_actor_and_date on author, committer, and tagger lines. Attackers can serve repositories with commit or tag objects containing long space-filled lines lacking a valid epoch or timezone, causing quadratic backtracking and CPU exhaustion.
NVD references (3)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.