GHSA-q2q7-5pp4-w6pg is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in urllib3. O3 Security confirms whether GHSA-q2q7-5pp4-w6pg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Catastrophic backtracking in URL authority parser when passed URL containing many @ characters
Real-World Exposure
urllib3Real-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
Impact
When provided with a URL containing many @ characters in the authority component the authority regular expression exhibits catastrophic backtracking causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.
Patches
The issue has been fixed in urllib3 v1.26.5.
References
For more information
If you have any questions or comments about this advisory:
- Ask in our community Discord
- Email [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | urllib3 | ≥ 1.25.4&&< 1.26.5 | 1.26.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for urllib3. 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 urllib3 to 1.26.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q2q7-5pp4-w6pg 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-q2q7-5pp4-w6pg 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-q2q7-5pp4-w6pg. 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.
* Red Hat OpenShift Container Platform (OCP) 4 delivers the python-urllib3 package which includes a vulnerable version of urllib3 module, however from OCP 4.6 the python-urllib3 package is no longer shipped. OCP 4.5 is out of support scope for Moderate and Low impact vulnerabilities, hence is marked Out Of Support…
Frequently Asked Questions
Is GHSA-q2q7-5pp4-w6pg in your dependencies?
O3 detects GHSA-q2q7-5pp4-w6pg across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.