CVE-2023-39663
HIGHCVE-2023-39663 is a high-severity (CVSS 7.5) CWE-1333 vulnerability in mathjax. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2023-39663 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
MathJax Regular expression Denial of Service (ReDoS)
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
mathjaxnpmDescription
Mathjax up to v2.7.9 was discovered to contain two Regular expression Denial of Service (ReDoS) vulnerabilities in MathJax.js via the components pattern and markdownPattern. NOTE: the vendor disputes this because the regular expressions are not applied to user input; thus, there is no risk.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mathjax | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mathjax. 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.
Remediation status
No patched version of mathjax has shipped for CVE-2023-39663 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 CVE-2023-39663 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 CVE-2023-39663. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-39663 in your dependencies?
O3 detects CVE-2023-39663 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.