GHSA-4qw4-jpp4-8gvp
Unbounded resource exhaustion in cmark-gfm autolink extension may lead to denial of service
Blast Radius
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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 | 0.23.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for commonmarker. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 pinpoints whether GHSA-4qw4-jpp4-8gvp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
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 detects GHSA-4qw4-jpp4-8gvp across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.