Vulnerability in Jsrsasign Project
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. 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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.005 (38.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Jsrsasign Project
- Kjur Jsrsasign
- Jsrsasign — versions 0
- Org.webjars.npm:jsrsasign — versions 0
Weakness classification (CWE)
References
- security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370941 (Third Party Advisory)
- gist.github.com/Kr0emer/93789fe6efe5519db9692d4ad1dad586 (Exploit, Third Party Advisory, Mitigation)
- github.com/kjur/jsrsasign/pull/645 (Issue Tracking)
- github.com/kjur/jsrsasign/commit/0710e392ec35de697ce11e4219c988ba2b5fe0eb (Patch)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-4601?
- CVE-2026-4601 is a high-severity vulnerability in Jsrsasign Project, classified under Missing Cryptographic Step. CVSS score: 8.7/10. Published 2026-03-23.
- How severe is CVE-2026-4601?
- High severity. CVSS v3 base score is 8.7 out of 10.