{"id":"GHSA-8qwj-4jxw-m8jw","summary":"jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass","details":"Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative exponents in ext/jsbn2.js. An attacker can force the computation of incorrect modular inverses and break signature verification by calling modPow with a negative exponent.","aliases":["CVE-2026-4602"],"modified":"2026-07-21T14:00:32.751983961Z","published":"2026-03-23T06:30:29Z","database_specific":{"github_reviewed_at":"2026-03-30T19:30:01Z","nvd_published_at":"2026-03-23T06:16:22Z","cwe_ids":["CWE-681"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4602"},{"type":"WEB","url":"https://github.com/kjur/jsrsasign/pull/650"},{"type":"WEB","url":"https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195"},{"type":"WEB","url":"https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175"},{"type":"WEB","url":"https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812274"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4602.json"},{"type":"PACKAGE","url":"https://github.com/kjur/jsrsasign"},{"type":"WEB","url":"https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2450206"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-4602"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:6926"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:6912"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:6720"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:6568"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:19410"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:19409"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:19375"}],"affected":[{"package":{"name":"jsrsasign","ecosystem":"npm","purl":"pkg:npm/jsrsasign"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"11.1.1"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-8qwj-4jxw-m8jw/GHSA-8qwj-4jxw-m8jw.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P"}]}