---
id: CVE-2026-103923
title: >-
  KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the
  web
summary: >-
  KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the
  web. From 0.11.0 until 0.18.2, KaTeX uses ordinary JavaScript property access
  for the renderer options object, the trust setting, default and processor
  setting…
severity: low
cvss: 2.1
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'
cwe:
  - CWE-807
vendor: KaTeX
product: KaTeX
affected:
  - 'KaTeX >= 0.11.0, < 0.18.2'
published: '2026-10-01'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T18:17:13.053'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-103923'
references:
  - url: >-
      https://github.com/KaTeX/KaTeX/commit/0adf7e77db6915d991803b29699f82b1ccf8d4f4
    label: security-advisories@github.com
  - url: 'https://github.com/KaTeX/KaTeX/pull/4260'
    label: security-advisories@github.com
  - url: 'https://github.com/KaTeX/KaTeX/releases/tag/v0.18.2'
    label: security-advisories@github.com
  - url: 'https://github.com/KaTeX/KaTeX/security/advisories/GHSA-238p-pmpm-9mq7'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-10-01T18:55:42.368Z'
---

## Overview

KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web. From 0.11.0 until 0.18.2, KaTeX uses ordinary JavaScript property access for the renderer options object, the trust setting, default and processor setting metadata, and namespace lookup and group restoration, allowing inherited properties to be treated as explicitly supplied values. When Object.prototype is already polluted or an attacker controls the options object's prototype, attacker-controlled mathematical expressions can use an inherited trust value to enable trusted rendering and produce links capable of user-interaction cross-site scripting or loading attacker-selected external resources in a consuming application that inserts unsanitized KaTeX output into a page. KaTeX does not itself create the prototype pollution, and rendering an expression alone does not execute script. This issue is fixed in version 0.18.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.