CyberSecBulletin
CVE-2026-4601NVD status: Modified

jsrsasign: Missing Cryptographic Step

Published Updated By the CyberSecBulletin desk

CVE-2026-4601 is a critical-severity missing cryptographic step vulnerability in jsrsasign, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 11.1.1 as the first without the flaw, so updating jsrsasign to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update jsrsasign to 11.1.1 or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Jsrsasignjsrsasignbefore 11.1.111.1.1
Org.webjars.npm:jsrsasignorg.webjars.npm:jsrsasignall versionsNot stated
Red HatMigration Toolkit for Virtualization 2.1Not specified in the recordNot stated
Red HatMigration Toolkit for Virtualization 2.9Not specified in the recordNot stated
Red HatRed Hat Quay 3.10Not specified in the recordNot stated
Red HatRed Hat Quay 3.12Not specified in the recordNot stated
Red HatRed Hat Quay 3.15Not specified in the recordNot stated
Red HatRed Hat Quay 3.16Not specified in the recordNot stated
Red HatRed Hat Quay 3.9Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.08.8HighCNA (snyk.io)
CVSS 3.18.7HighCNA (snyk.io)
CVSS 3.19.1CriticalNVD
CVSS 3.18.7HighCNA

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Cryptographic Step

The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.

More Missing Cryptographic Step vulnerabilities (CWE-325)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in jsrsasign

All jsrsasign vulnerabilities

Recent Missing Cryptographic Step vulnerabilities

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