GitHub Advisoryadvisory · npm

GHSA-8qwj-4jxw-m8jw jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass

HIGH Published 2026-03-23 Modified 2026-07-21 Official page ↗
Aliases
CVE-2026-4602
Ecosystem
npm
Packages
jsrsasign
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-681
Reviewed
2026-03-30

Affected packages

• npm jsrsasign: < 11.1.1 → fixed in 11.1.1

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.

Related

Alias · CVE (1)

  • CVE-2026-4602 Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative… vulnerability

Weakness · CWE (1)

  • CWE-681 Incorrect Conversion between Numeric Types weakness

References