What’s Vulnerable › Vulnerabilities

CVE-2026-4602

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-23 · updated 2026-09-10
• Weakness: CWE-681

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 products

• jsrsasign: before 11.1.1 — fixed in 11.1.1

How to fix

Upgrade to a fixed version: jsrsasign 11.1.1. Check the vendor advisory for mitigations.

References

• 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

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