GHSA-9w8r-397f-prfh is a high-severity (CVSS 7.5) CWE-835 vulnerability in pygments. O3 Security confirms whether GHSA-9w8r-397f-prfh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Infinite Loop in Pygments
Real-World Exposure
pygmentsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pygments | ≥ 1.5&&< 2.7.4 | 2.7.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pygments. 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 pygments to 2.7.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9w8r-397f-prfh 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-9w8r-397f-prfh 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-9w8r-397f-prfh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
In OpenShift Container Platform 3.11, the vulnerable version of python-pygments is embedded in the google-cloud-sdk package, which is shipped in the openshift-ansible container (aos3-installation-container). As the access to the openshift-ansible container is restricted only to cluster administrators, this component…
Frequently Asked Questions
Is GHSA-9w8r-397f-prfh in your dependencies?
O3 detects GHSA-9w8r-397f-prfh across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.