CVE-2026-4600 | THREATINT

Description

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.

PUBLISHED Reserved 2026-03-22 | Published 2026-03-23 | Updated 2026-03-23 | Assigner snyk

CRITICAL: 9.1CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

HIGH: 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:P

Problem types

Improper Verification of Cryptographic Signature

Credits

Kr0emer

References

gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7 exploit

security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370940

gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7

github.com/kjur/jsrsasign/pull/646

github.com/...ommit/37b4c06b145c7bfd6bc2a6df5d0a12c56b15ef60

cve.org (CVE-2026-4600)

nvd.nist.gov (CVE-2026-4600)

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