What’s Vulnerable › Vulnerabilities

CVE-2025-23207: \htmlData does not validate attribute names in KaTeX

• Severity: high (CVSS 7.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-01-17 · updated 2026-06-17
• Weakness: CWE-116

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.

Affected products

• KaTeX: from 0.12.0 before 0.16.21 — fixed in 0.16.21

How to fix

Upgrade to a fixed version: KaTeX 0.16.21. Check the vendor advisory for mitigations.

References

• https://github.com/KaTeX/KaTeX/commit/ff289955e81aab89086eef09254cbf88573d415c
• https://github.com/KaTeX/KaTeX/security/advisories/GHSA-cg87-wmx4-v546

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