CVE-2026-4600
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).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.1 HIGHCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.36% probability · 30th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Affected
- kjur/jsrsasign
- Source
- report@snyk.io
EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7Exploit, Mitigation, Third Party Advisory
- https://github.com/kjur/jsrsasign/commit/37b4c06b145c7bfd6bc2a6df5d0a12c56b15ef60Patch
- https://github.com/kjur/jsrsasign/pull/646Issue Tracking
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812268
- https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370940Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:19375
- https://access.redhat.com/errata/RHSA-2026:19409
- https://access.redhat.com/errata/RHSA-2026:19410
- https://access.redhat.com/errata/RHSA-2026:6568
- https://access.redhat.com/errata/RHSA-2026:6720
- https://access.redhat.com/errata/RHSA-2026:6912
- https://access.redhat.com/errata/RHSA-2026:6926
- https://access.redhat.com/security/cve/CVE-2026-4600
- https://bugzilla.redhat.com/show_bug.cgi?id=2450208
- https://gist.github.com/Kr0emer/bf15ddc097176e951659a24a8e9002a7Exploit, Mitigation, Third Party Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4600.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.