HighGHSA-8qwj-4jxw-m8jwCVE-2026-4602

jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass

Published 23 Mar 2026 · Updated 21 Jul 2026

Affected package

Affected: <11.1.1
Fixed in: 11.1.1

Update to the fixed version for your release line, for example:npm install jsrsasign@11.1.1

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.

Is GHSA-8qwj-4jxw-m8jw in any of your client repos?

Checking one package by hand is fine. Checking it across forty client projects is not. NPMscan reads the lockfiles in every GitHub repo you pick, finds each project with an affected jsrsasign, and gives you the command that fixes it.

Scan a project free, no signup Or connect GitHub to scan every repo

References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.