jsrsasign: DSA signatures or X.509 certificates can be forged via DSA domain-parameter validation in KJUR.crypto.DSA.setPublic

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.1 · CVSS: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 · score source

EPSS

• CVE-2026-4600: 0.36% estimated exploitation activity in the next 30 days; percentile 29.82 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 by the source

23 Mar 2026, 06:30 UTC

Last modified by the source

21 Jul 2026, 15:15 UTC

Source last checked

26 Oct 2026, 12:57 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-wvqx-v3f6-w8rh

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-wvqx-v3f6-w8rh

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# Patch Next advisory brief: CVE-2026-4600

Advisory: jsrsasign: DSA signatures or X.509 certificates can be forged via DSA domain-parameter validation in KJUR.crypto.DSA.setPublic
IDs: CVE-2026-4600, GHSA-wvqx-v3f6-w8rh
Record: https://patchnext.com/advisories/cve-2026-4600 (revision 3, source checked 26 Oct 2026, 12:57 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jsrsasign 11.1.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm jsrsasign: affected < 11.1.1; fixed in 11.1.1

## Suggested inspection (read-only)
- `npm ls jsrsasign --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on jsrsasign.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-wvqx-v3f6-w8rh (OSV record GHSA-wvqx-v3f6-w8rh lists affected ranges: npm jsrsasign >=0 <11.1.1 (fixed))
- Verified: https://github.com/advisories/GHSA-wvqx-v3f6-w8rh (GitHub-reviewed advisory GHSA-wvqx-v3f6-w8rh lists affected ranges: npm jsrsasign >=0 <11.1.1)

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