GHSA-h2fp-xgx6-xh6f is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in werkzeug. A fix is available for werkzeug — see the affected versions and patch details below.
Pallets Werkzeug cross-site scripting vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-h2fp-xgx6-xh6f plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
werkzeugReal-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
Cross-site scripting (XSS) vulnerability in the render_full function in debug/tbtools.py in the debugger in Pallets Werkzeug before 0.11.11 (as used in Pallets Flask and other products) allows remote attackers to inject arbitrary web script or HTML via a field that contains an exception message.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | werkzeug | all versions | 0.11.11pip install --upgrade 'werkzeug==0.11.11' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for werkzeug, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update werkzeug to 0.11.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h2fp-xgx6-xh6f 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-h2fp-xgx6-xh6f can be triaged on real exposure rather than presence alone.
Tailored to GHSA-h2fp-xgx6-xh6f. 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.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Satellite 6.6 for RHEL 7 | ansiblerole-foreman_scap_client-0:0.0.3-1.el7sat | RHSA-2019:3172 |
Frequently Asked Questions
Is GHSA-h2fp-xgx6-xh6f in your dependencies?
O3 Security finds GHSA-h2fp-xgx6-xh6f across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.