kjur/jsrsasign · Security
jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass
- GHSA ID
- GHSA-8qwj-4jxw-m8jw
- CVE ID
- CVE-2026-4602
- Severity
- high
- Published
- Updated
- CVSS
- 7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS v3
- 7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS v4
- 7.7 · 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
Description
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.
CWEs
- CWE-681 · Incorrect Conversion between Numeric Types
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-4602 ↗
- https://github.com/kjur/jsrsasign/pull/650 ↗
- https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195 ↗
- https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5 ↗
- https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175 ↗
- https://access.redhat.com/errata/RHSA-2026:19375 ↗
- https://access.redhat.com/errata/RHSA-2026:19409 ↗
- https://access.redhat.com/errata/RHSA-2026:19410 ↗
- https://access.redhat.com/errata/RHSA-2026:6568 ↗
- https://access.redhat.com/errata/RHSA-2026:6720 ↗
- https://access.redhat.com/errata/RHSA-2026:6912 ↗
- https://access.redhat.com/errata/RHSA-2026:6926 ↗
- https://access.redhat.com/security/cve/CVE-2026-4602 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2450206 ↗
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4602.json ↗
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812274 ↗
- https://github.com/advisories/GHSA-8qwj-4jxw-m8jw ↗