PT-2026-27058 · Jsrsasign · Jsrsasign

Kr0Emer · Published 2026-03-23 · Updated 2026-03-23 · CVE-2026-4602

Mitre

CVSS v3.1

7.5

High

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Exploit

Fix

Weakness Enumeration

CWE-681

Related Identifiers

CVE-2026-4602

Affected Products

Jsrsasign

References · 7

• 🔥 https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5 · Exploit
• https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-4602 · Security Note
• https://github.com/kjur/jsrsasign/pull/650 · Note
• https://twitter.com/CVEnew/status/2035992479451816147 · Twitter Post
• https://twitter.com/VulmonFeeds/status/2035970908599312589 · Twitter Post
• https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175 · Note