PT-2026-27056 · Jsrsasign · Jsrsasign

Kr0Emer · Published 2026-03-23 · Updated 2026-03-23 · CVE-2026-4600

Mitre

CVSS v3.1

7.4

High

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

Versions of the package jsrsasign before 11.1.1 are vulnerable to Improper Verification of Cryptographic Signature via the DSA domain-parameter validation in KJUR.crypto.DSA.setPublic (and the related DSA/X509 verification flow in src/dsa-2.0.js). An attacker can forge DSA signatures or X.509 certificates that X509.verifySignature() accepts by supplying malicious domain parameters such as g=1, y=1, and a fixed r=1, which make the verification equation true for any hash.

Exploit

Fix

Improper Verification of Cryptographic Signature

Weakness Enumeration

CWE-347

Related Identifiers

CVE-2026-4600

Affected Products

Jsrsasign

References · 6

• 🔥 https://gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7 · Exploit
• https://github.com/kjur/jsrsasign/commit/37b4c06b145c7bfd6bc2a6df5d0a12c56b15ef60 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-4600 · Security Note
• https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370940 · Note
• https://github.com/kjur/jsrsasign/pull/646 · Note
• https://twitter.com/CVEnew/status/2035992480596804088 · Twitter Post