CVE-2025-23207 \htmlData does not validate attribute names in KaTeX
Attackers can execute arbitrary JavaScript via malicious TeX input in KaTeX when the trust option is enabled, requiring an upgrade or configuration change.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-23207?
CVE-2025-23207 is a medium-severity cross-site scripting vulnerability in KaTeX, published on 17 Jan 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web. KaTeX users who render untrusted mathematical expressions with `renderToString` could encounter malicious input using `\htmlData` that runs arbitrary JavaScript, or generate invalid HTML. Users are advised to upgrade to KaTeX v0.16.21 to remove this vulnerability. Users unable to upgrade should avoid use of or turn off the `trust` option, or set it to forbid `\htmlData` commands, forbid inputs containing the substring `"\\htmlData"` and sanitize HTML output from KaTeX.
Which versions are affected by CVE-2025-23207?
2 open source packages ship an affected version, including katex. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
katex npm | From 0.12.0 | 0.16.21 |
katex npm | From 0.12.0 | 0.16.21 |
Products include Katex Katex.
How do I fix CVE-2025-23207?
Upgrade katex to 0.16.21 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-23207 being exploited?
There is no known exploitation of CVE-2025-23207 in the wild and no public exploit code.
Other vulnerabilities in KaTeX
Sources
Also known as DEBIAN-CVE-2025-23207, GHSA-cg87-wmx4-v546, UBUNTU-CVE-2025-23207.