CVE-2026-4601: jsrsasign Missing Cryptographic Validation During DSA Vulnerability

HIGH
Advisory Identifier: GHSA-w8q8-93cx-6h7r
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CVSS 8.7
CWE-325
Published
Advisory Summary

CVE-2026-4601 is a HIGH (CVSS 8.7) missing cryptographic validation during dsa vulnerability (CWE-325: Missing Cryptographic Step) affecting jsrsasign libraries in the npm ecosystem. The issue involves missing cryptographic validation during dsa signing enables private key extraction. Remediation is available by upgrading affected packages to version 11.1.1.

CVE-2026-4601 at a Glance

CVE Identifier CVE-2026-4601
GHSA Identifier GHSA-w8q8-93cx-6h7r
Severity HIGH
CVSS v3.1 Base Score 8.7
CWE Classification CWE-325: Missing Cryptographic Step
Affected Product jsrsasign
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 8.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-4601

To remediate this vulnerability, upgrade all affected jsrsasign dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

jsrsasign fixed: 11.1.1 
npm install jsrsasign@11.1.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls jsrsasign

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-4601, inspect your project dependencies using npm:

npm ls jsrsasign

Analyze the terminal output to locate any version of jsrsasign in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 11.1.1), your application is affected.

Note: The npm ls jsrsasign command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-325: Missing Cryptographic Step, where the product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm. In jsrsasign, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-4601 Affected jsrsasign Versions

1 component(s)
Fixed Versions:
11.1.1
Product / Package Ecosystem Affected Versions Fixed Version
jsrsasign
npm/jsrsasign
npm
< 11.1.1
11.1.1

References

NVD — CVE-2026-4601 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4601
jsrsasign Source Repository REPOSITORY
https://github.com/kjur/jsrsasign/pull/645
Security Fix Commit FIX COMMIT
https://github.com/kjur/jsrsasign/commit/0710e392ec35de697ce11e4219c988ba2b5fe0eb
jsrsasign Source Repository REPOSITORY
https://gist.github.com/Kr0emer/93789fe6efe5519db9692d4ad1dad586
jsrsasign Source Repository REPOSITORY
https://github.com/kjur/jsrsasign
jsrsasign Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370941

Frequently Asked Questions

What is CVE-2026-4601?
CVE-2026-4601 is a security vulnerability in jsrsasign involving Missing cryptographic validation during DSA signing enables private key extraction under CWE-325: Missing Cryptographic Step.
Which jsrsasign versions are affected?
Affected versions include releases prior to 11.1.1 across affected packages: jsrsasign.
What version fixes CVE-2026-4601?
Upgrading to 11.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is jsrsasign affected?
Yes, jsrsasign is affected in releases prior to 11.1.1. Upgrade your dependency to 11.1.1 or later.
What is the CVSS score of CVE-2026-4601?
CVE-2026-4601 has a CVSS v3.1 base score of 8.7 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N.
What CWE is associated with CVE-2026-4601?
CVE-2026-4601 is classified under CWE-325: Missing Cryptographic Step (The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.).
How can I check npm dependencies for CVE-2026-4601?
Run the dependency tree command: 'npm ls jsrsasign'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w8q8-93cx-6h7r",
  "modified" : "2026-03-29T15:51:59Z",
  "published" : "2026-03-23T06:30:29Z",
  "aliases" : [ "CVE-2026-4601" ],
  "summary" : "jsrsasign: Missing cryptographic validation during DSA signing enables private key extraction",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:H/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "jsrsasign"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "11.1.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4601"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kjur/jsrsasign/pull/645"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kjur/jsrsasign/commit/0710e392ec35de697ce11e4219c988ba2b5fe0eb"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/Kr0emer/93789fe6efe5519db9692d4ad1dad586"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kjur/jsrsasign"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370941"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-325" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-29T15:51:59Z",
    "nvd_published_at" : "2026-03-23T06:16:21Z"
  }
}