CVE-2025-23207
Published: 17 January 2025
Summary
CVE-2025-23207 is a medium-severity Improper Encoding or Escaping of Output (CWE-116) vulnerability in Katex Katex. Its CVSS base score is 6.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 8.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
SI-10 requires input validation at interfaces, directly preventing malicious TeX expressions containing '\htmlData' from being processed by KaTeX's renderToString.
SI-15 mandates filtering of information output, aligning with sanitizing HTML output from KaTeX to block arbitrary JavaScript execution or invalid HTML.
SI-2 enforces timely flaw remediation, such as upgrading KaTeX to v0.16.21, which removes the vulnerability in handling untrusted inputs.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability allows execution of arbitrary JavaScript via malicious \htmlData in untrusted input rendered by KaTeX's renderToString, enabling exploitation of client-side software vulnerabilities for code execution in web browsers.
NVD 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…
more
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.
Deeper analysisAI
CVE-2025-23207 is a vulnerability in KaTeX, a JavaScript library for rendering TeX mathematical expressions on the web. It affects KaTeX users who invoke the `renderToString` function on untrusted mathematical input, allowing malicious expressions containing the `\htmlData` command to execute arbitrary JavaScript or produce invalid HTML output. The issue is rated with a CVSS v3.1 base score of 6.3 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L) and is associated with CWE-116 (Improper Encoding or Escaping of Output) and CWE-79 (Cross-site Scripting).
An attacker can exploit this vulnerability over the network with low complexity and low privileges required, without needing user interaction and without changing the scope. By supplying crafted mathematical input containing `\htmlData` to a targeted application using KaTeX's `renderToString`, the attacker achieves low-impact confidentiality, integrity, and availability effects, primarily through arbitrary JavaScript execution (such as cross-site scripting) or malformed HTML generation.
The KaTeX security advisory and related commit recommend upgrading to version 0.16.21, which removes the vulnerability. For users unable to upgrade, mitigations include avoiding or disabling the `trust` option, configuring it to forbid `\htmlData` commands, rejecting inputs containing the substring `"\\htmlData"`, and sanitizing the resulting HTML output from KaTeX. Details are available in the GitHub security advisory (GHSA-cg87-wmx4-v546) and the fixing commit (ff289955e81aab89086eef09254cbf88573d415c).
Details
- CWE(s)