CVE-2021-26541 is a critical-severity (CVSS 9.8) OS Command Injection vulnerability in gitlog. 1 public exploit reference exists, so weaponization risk is real. A fix is available for gitlog — see the affected versions and patch details below.
Command injection in gitlog
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-26541 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
gitlognpmDescription
The gitlog function in src/index.ts in gitlog before 4.0.4 has a command injection vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | gitlog | all versions | 4.0.4npm install gitlog@4.0.4 |
Affected Products
gitloggitlog_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gitlog, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gitlog to 4.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-26541 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2021-26541 in your dependencies?
Find it across npm, including transitive dependencies.