{"cve":"CVE-2026-63430","nvd":{"published":"2026-10-15T19:17:42.367","modified":"2026-10-16T16:00:33.533","status":"Awaiting Analysis","description":"ammonia is a Rust library for repairing and securing untrusted HTML. Prior to 3.3.2, 4.0.2, and 4.1.3, applications that explicitly allow the math tag, annotation-xml, and at least one raw-text HTML element while disallowing the encoding attribute can permit mutation cross-site scripting. ammonia does not correctly implement annotation-xml's encoding-dependent MathML integration-point behavior after attribute filtering removes encoding, so the sanitizer validates a descendant under one namespace interpretation while the browser reparses the output under another. An attacker can use that namespace transition and an allowed raw-text HTML element to execute JavaScript when a user renders the sanitized output. The required tags are not enabled by default, so applications that do not explicitly allow them are not affected. This issue is fixed in versions 3.3.2, 4.0.2, and 4.1.3.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","score":6.3},"cvss_v3":null,"cwes":["CWE-79"],"references":["https://github.com/rust-ammonia/ammonia/commit/004bf2cee4288f74a6ee619d589e3e90c24c09ca","https://github.com/rust-ammonia/ammonia/commit/7ac3fd3145236f28857eeecbadb544c8659cba31","https://github.com/rust-ammonia/ammonia/commit/b51bf4f9749ed3cd518330105f20a2c39c9ee274","https://github.com/rust-ammonia/ammonia/pull/243","https://github.com/rust-ammonia/ammonia/pull/244"],"products":[],"source":"nvd","synced_at":"2026-10-19T23:00:53.604569364+00:00"},"epss":{"cve":"CVE-2026-63430","score":0.00555,"percentile":0.46023,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-9jh8-v38h-cvhr","url":"https://osv.dev/vulnerability/GHSA-9jh8-v38h-cvhr","summary":"ammonia: mXSS  via MathML `annotation-xml` encoding strip","modified":"2026-10-22T14:16:23.103650626Z","packages":[{"ecosystem":"crates.io","name":"ammonia","purl":"pkg:cargo/ammonia","ranges":["<3.3.2"],"fixed":["3.3.2"]},{"ecosystem":"crates.io","name":"ammonia","purl":"pkg:cargo/ammonia","ranges":[">=4.0.0 <4.0.2"],"fixed":["4.0.2"]},{"ecosystem":"crates.io","name":"ammonia","purl":"pkg:cargo/ammonia","ranges":[">=4.1.0 <4.1.3"],"fixed":["4.1.3"]}]},{"id":"RUSTSEC-2026-0193","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0193","summary":"mXSS in ammonia via MathML `annotation-xml` encoding strip","modified":"2026-07-17T05:41:42.316382038Z","packages":[{"ecosystem":"crates.io","name":"ammonia","purl":"pkg:cargo/ammonia","ranges":[">=0.0.0-0 <3.3.2",">=4.0.0 <4.0.2",">=4.1.0 <4.1.3"],"fixed":["3.3.2","4.0.2","4.1.3"]}]}],"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."]}