GHSA-4qw4-jpp4-8gvp — commonmarker
Fix: gjtorikian/commonmarker#190GHSA-4qw4-jpp4-8gvp is a security vulnerability in commonmarker. A fix is available for commonmarker — see the affected versions and patch details below.
Unbounded resource exhaustion in cmark-gfm autolink extension may lead to denial of service
Real-World Exposure
commonmarkerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Impact
CommonMarker uses cmark-gfm for rendering Github Flavored Markdown. A polynomial time complexity issue in cmark-gfm's autolink extension may lead to unbounded resource exhaustion and subsequent denial of service.
Patches
This vulnerability has been patched in the following CommonMarker release:
- v0.23.6
Workarounds
Disable use of the autolink extension.
References
https://github.com/gjtorikian/commonmarker/pull/190 https://github.com/github/cmark-gfm/security/advisories/GHSA-cgh3-p57x-9q7q https://en.wikipedia.org/wiki/Time_complexity
For more information
If you have any questions or comments about this advisory:
- Open an issue in github/cmark-gfm
Acknowledgements
We would like to thank Legit Security for reporting this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | commonmarker | all versions | 0.23.6bundle update commonmarker --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for commonmarker, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update commonmarker to 0.23.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4qw4-jpp4-8gvp is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4qw4-jpp4-8gvp can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4qw4-jpp4-8gvp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-4qw4-jpp4-8gvp in your dependencies?
O3 Security finds GHSA-4qw4-jpp4-8gvp across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.