GHSA-cg87-wmx4-v546
MEDIUMKaTeX \htmlData does not validate attribute names
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
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
katexnpmDescription
Impact
KaTeX users who render untrusted mathematical expressions with renderToString could encounter malicious input using \htmlData that runs arbitrary JavaScript, or generate invalid HTML.
Patches
Upgrade to KaTeX v0.16.21 to remove this vulnerability.
Workarounds
- Avoid use of or turn off the
trustoption, or set it to forbid\htmlDatacommands. - Forbid inputs containing the substring
"\\htmlData". - Sanitize HTML output from KaTeX.
Details
\htmlData did not validate its attribute name argument, allowing it to generate invalid or malicious HTML that runs scripts.
For more information
If you have any questions or comments about this advisory:
- Open an issue or security advisory in the KaTeX repository
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | katex | ≥ 0.12.0&&< 0.16.21 | 0.16.21 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for katex. 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 katex to 0.16.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cg87-wmx4-v546 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-cg87-wmx4-v546 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-cg87-wmx4-v546. 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-cg87-wmx4-v546 in your dependencies?
O3 detects GHSA-cg87-wmx4-v546 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.