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.
https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370940
https://github.com/kjur/jsrsasign/pull/646
https://github.com/kjur/jsrsasign/commit/37b4c06b145c7bfd6bc2a6df5d0a12c56b15ef60
https://gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7
Published: 2026-03-23
Updated: 2026-03-23
Base Score: 9.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N
Severity: High
Base Score: 9.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity: Critical
Base Score: 9.1
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: Critical
EPSS: 0.00012