PT-2026-27056 · Jsrsasign · Jsrsasign

Kr0Emer · CVE-2026-4600 · Published 2026-03-23 · Updated 2026-07-20

Positive Technologies (AI Summary)

CVSS v3.1

8.2

High

Base vector

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

Name of the Vulnerable Software and Affected Versions jsrsasign versions prior to 11.1.1

Description Improper verification of cryptographic signatures occurs due to flawed DSA domain-parameter validation in the KJUR.crypto.DSA.setPublic() function and the associated DSA/X509 verification flow in src/dsa-2.0.js. An attacker can forge DSA signatures or X.509 certificates that the X509.verifySignature() function accepts by providing malicious domain parameters, specifically g=1, y=1, and a fixed r=1, which causes the verification equation to be true for any hash.

Recommendations Update jsrsasign to version 11.1.1 or later.

Exploit

Fix

Improper Verification of Cryptographic Signature

Weakness Enumeration

CWE-347

Related Identifiers

CVE-2026-4600

GHSA-WVQX-V3F6-W8RH

Affected Products

Jsrsasign

References · 28

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4600.json · Exploit
• 🔥 https://gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7 · Exploit
• https://github.com/kjur/jsrsasign/commit/37b4c06b145c7bfd6bc2a6df5d0a12c56b15ef60 · Patch
• https://osv.dev/vulnerability/GHSA-wvqx-v3f6-w8rh · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:6720 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:19409 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-4600 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:6568 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:19410 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:6926 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:19375 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2026:6912 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4600 · Security Note
• https://github.com/kjur/jsrsasign/pull/646 · Note
• https://github.com/kjur/jsrsasign · Note