{"id":"CVE-2026-4603","aliases":["GHSA-464q-cqxq-xhgr"],"url":"https://o3.security/vulnerability/CVE-2026-4603","summary":"jsrsasign: Division by Zero Allows Invalid JWK Modulus to Cause Deterministic Zero Output in RSA Operations","details":"Versions of the package jsrsasign before 11.1.1 are vulnerable to Division by zero due to the RSASetPublic/KEYUTIL parsing path in ext/rsa.js and the BigInteger.modPowInt reduction logic in ext/jsbn.js. An attacker can force RSA public-key operations (e.g., verify and encryption) to collapse to deterministic zero outputs and hide “invalid key” errors by supplying a JWK whose modulus decodes to zero.","published":"2026-03-23T05:00:14.060Z","modified":"2026-07-15T01:49:02.541105534Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"jsrsasign","fixedVersion":"11.1.1"}],"fix":{"url":"https://github.com/kjur/jsrsasign/commit/dc41d49fac4297e7a737a3ef8ebd0aa9c49ef93f","label":"kjur/jsrsasign@dc41d49"},"references":[{"type":"WEB","url":"https://gist.github.com/Kr0emer/5366b7364c4fbf7e754bc377f321e9f3"},{"type":"WEB","url":"https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371176"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4603.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4603"},{"type":"FIX","url":"https://github.com/kjur/jsrsasign/commit/dc41d49fac4297e7a737a3ef8ebd0aa9c49ef93f"},{"type":"FIX","url":"https://github.com/kjur/jsrsasign/pull/649"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:02.541105534Z"}}