Critical severity · published Mar 23, 2026
CVE-2026-4601
Versions of the package jsrsasign before 11.1.1 are vulnerable to Missing Cryptographic Step via the KJUR.crypto.DSA.signWithMessageHash process in the DSA signing implementation
9.1
CVSS
0.3%
EPSS
No
On KEV
Description
Versions of the package jsrsasign before 11.1.1 are vulnerable to Missing Cryptographic Step via the KJUR.crypto.DSA.signWithMessageHash process in the DSA signing implementation. An attacker can recover the private key by forcing r or s to be zero, so the library emits an invalid signature without retrying, and then solves for x from the resulting signature.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 23% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JS
jsrsasign ·
before 11.1.1 · source: vendor, NVD
OR
org.webjars.npm:jsrsasign ·
0 · source: vendor
MT
Migration Toolkit for Virtualization 2.1 · Red Hat
All versions, or not specified · source: CISA
MT
Migration Toolkit for Virtualization 2.9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Quay 3.10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Quay 3.12 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Quay 3.15 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Quay 3.16 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Quay 3.9 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4601
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-4601
Exploit
https://gist.github.com/Kr0emer/93789fe6efe5519db9692d4ad1dad586
Patch
https://github.com/kjur/jsrsasign/commit/0710e392ec35de697ce11e4219c988ba2b5fe0eb
Issue Tracking
https://github.com/kjur/jsrsasign/pull/645
security.snyk.io
https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812269
Third Party Advisory
https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370941
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:19375
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