GHSA-h5c8-rqwp-cp95
MEDIUMJinja vulnerable to HTML attribute injection when passing user input as keys to xmlattr filter
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.
Blast Radius
jinja2Real-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
The xmlattr filter in affected versions of Jinja accepts keys containing spaces. XML/HTML attributes cannot contain spaces, as each would then be interpreted as a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. Note that accepting keys as user input is not common or a particularly intended use case of the xmlattr filter, and an application doing so should already be verifying what keys are provided regardless of this fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | jinja2 | all versions | 3.1.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jinja2. 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 jinja2 to 3.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h5c8-rqwp-cp95 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-h5c8-rqwp-cp95 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-h5c8-rqwp-cp95. 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-h5c8-rqwp-cp95 in your dependencies?
O3 detects GHSA-h5c8-rqwp-cp95 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.