{"cve":"CVE-2026-103923","nvd":{"published":"2026-10-01T18:17:13.053","modified":"2026-10-06T02:17:02.757","status":"Awaiting Analysis","description":"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.","cvss_v4":{"vector":"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","score":2.1},"cvss_v3":null,"cwes":["CWE-807"],"references":["https://github.com/KaTeX/KaTeX/commit/0adf7e77db6915d991803b29699f82b1ccf8d4f4","https://github.com/KaTeX/KaTeX/pull/4260","https://github.com/KaTeX/KaTeX/releases/tag/v0.18.2","https://github.com/KaTeX/KaTeX/security/advisories/GHSA-238p-pmpm-9mq7"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:57:46.668721662+00:00"},"epss":{"cve":"CVE-2026-103923","score":0.003,"percentile":0.22433,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-238p-pmpm-9mq7","url":"https://osv.dev/vulnerability/GHSA-238p-pmpm-9mq7","summary":"KaTeX: Existing prototype pollution can bypass trust restrictions","modified":"2026-10-06T00:00:09.544490390Z","packages":[{"ecosystem":"npm","name":"katex","purl":"pkg:npm/katex","ranges":[">=0.11.0 <0.18.2"],"fixed":["0.18.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}