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CVE Record

CVE-2026-4601: Versions of the package jsrsasign before 11.1.1 are vulnerable to Missing Cryptographic Step via the KJUR.c...

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.

CriticalCVSS 9.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

jsrsasign before 11.1.1 can produce a broken DSA signature in a way that exposes the signing private key. If a system uses this library for DSA signing, compromise could let an attacker forge signatures and undermine trust decisions.

Executive priority

Treat as urgent where jsrsasign performs DSA signing for authentication, identity, documents, tokens, or software integrity. Key recovery changes the response from a routine library update to potential credential compromise assessment.

Technical view

The issue is a missing cryptographic retry step in KJUR.crypto.DSA.signWithMessageHash. When r or s becomes zero, vulnerable versions emit an invalid signature instead of retrying. The source description says that condition can allow recovery of the DSA private key.

Likely exposure

Exposure is most likely in JavaScript or Node.js applications that use jsrsasign before 11.1.1 for DSA signing. Systems only using other algorithms or not invoking DSA signing may not be practically exposed, but dependency inventories should confirm actual use.

Exploitation context

The CVE is not listed as KEV in the provided bundle. Public references include Snyk, a GitHub pull request, a fixing commit, and a public gist, but the bundle does not prove active exploitation in the wild.

Researcher notes

Focus triage on reachability of KJUR.crypto.DSA.signWithMessageHash and whether attackers can influence signing inputs. CVSS 4.0 is 9.4 with high confidentiality and integrity impact, high attack complexity, and proof-of-concept maturity in the provided metadata.

Mitigation direction

  • Upgrade jsrsasign to version 11.1.1 or later.
  • Regenerate affected DSA signing keys if vulnerable signing may have occurred.
  • Review Red Hat advisories for packaged or downstream exposure.
  • Check vendor guidance before applying compensating controls.
  • Prioritize systems where signatures grant authentication or integrity trust.

Validation and detection

  • Search SBOMs and lockfiles for jsrsasign below 11.1.1.
  • Confirm whether affected applications call DSA signing functions.
  • Identify services that expose signing workflows to untrusted inputs.
  • Review logs for anomalous DSA signing activity where available.
  • Verify upgraded builds no longer include vulnerable versions.
Prepared
Confidence
high
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-325: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-4601 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.4 (4.0)
Known Exploited
No
Published

Vector: 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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

3CVSS vectors
5Timeline events
2ADP providers
15Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

3 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.4CVSS 4.0CriticalCVSS: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——snyk
8.7CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N/E:P2.25.8snyk
8.7CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N2.25.8redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

9.4Critical
CVSS 4.0 vector shape for CVE-2026-4601Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: 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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPjsrsasign: jsrsasign: Private Key Recovery via Missing Cryptographic Step in DSA Signing
other:Red Hat severity ratingcvssV3_1
  • 2026-03-23T06:01:44.014Z: Reported to Red Hat.
  • 2026-03-23T05:00:13.312Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/ajsrsasign0Listed
Weakness

CWE details

CWE-325

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-325 · source CWE mapping

Missing Cryptographic Step

Missing Cryptographic Step represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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