CVE-2026-4602
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
0.9%
57.2th percentile
CISA KEV
Not listed
Weakness / dates
CWE-681
Published 2026-03-23 · modified 2026-09-10
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.
Affected
References
- exploit https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5
- https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195
- https://github.com/kjur/jsrsasign/pull/650
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812274
- 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