Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:LSummary
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 Browser Session Hijacking (T1185); ranked at the 34th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
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).
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-0112
Vulnerability Data
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.
Input validation directly enforces neutralization of untrusted data before it reaches web output generation.
Output filtering can catch or sanitize unneutralized script content before it is served to users.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require proper output encoding to prevent injection and message malformation.
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding standards explicitly require correct output encoding and escaping to preserve message structure.
Security testing can detect missing or incorrect encoding but does not itself implement the control.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.
Secure development life cycle mandates output encoding/escaping practices that directly prevent improper encoding.
Application security requirements include explicit rules for safe output handling and encoding.