Security readout for executives and security teams
Plain-English summary
CVE-2026-4599 affects jsrsasign, a JavaScript cryptography library. In vulnerable versions, DSA signature generation can produce biased random values. If an attacker can obtain enough affected signatures, the private signing key may be recoverable, creating a serious trust and identity risk.
Executive priority
Prioritize remediation for systems that use jsrsasign for DSA signing, especially authentication, document signing, token signing, or trust infrastructure. The business risk is private key compromise, not just application instability.
Technical view
jsrsasign versions from 7.0.0 before 11.1.1 have incomplete range checks in getRandomBigIntegerZeroToMax and getRandomBigIntegerMinToMax. Incorrect compareTo logic can accept out-of-range candidates, biasing DSA nonces during signature generation and potentially exposing private keys.
Likely exposure
Exposure is most likely in applications or packaged products using jsrsasign, including the npm package and org.webjars.npm:jsrsasign. Risk is highest where affected versions perform DSA signing and signatures are observable by an attacker.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. Public references include vulnerability records, a proof-oriented gist, a pull request, and a fixing commit. Treat exploitability as credible, but do not claim active exploitation from these sources.
Researcher notes
The weakness is nonce bias from incomplete comparison checks in random BigInteger generation. Focus validation on reachable DSA signing paths, dependency provenance, and whether signatures generated by vulnerable code were externally observable.
Mitigation direction
- Upgrade jsrsasign to 11.1.1 or later where directly used.
- Update org.webjars.npm:jsrsasign and downstream packages through vendor-supported releases.
- Apply relevant Red Hat errata where affected Red Hat products include this component.
- Review DSA keys used with vulnerable versions and rotate where exposure is plausible.
- Check vendor guidance for any product-specific backports or compensating controls.
Validation and detection
- Search npm, yarn, pnpm, and lock files for jsrsasign versions before 11.1.1.
- Check Maven or WebJars dependency trees for org.webjars.npm:jsrsasign.
- Identify whether affected applications perform DSA signature generation.
- Confirm deployed artifacts no longer contain vulnerable jsrsasign versions.
- Record any exposed DSA signing keys for rotation and audit decisions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1023: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-338: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-4599 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.3 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
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.
SSVC decision data
CVSS vector scores
3 official scoresWe 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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N——snykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2snykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2redhat-SADPVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-03-23T06:01:34.008Z: Reported to Red Hat.
- 2026-03-23T05:00:12.522Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370939CVE reference, snyk
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812264CVE reference, snyk
- https://gist.github.com/Kr0emer/081681818b51605c91945126d74b4f20CVE reference, snyk
- https://github.com/kjur/jsrsasign/pull/647CVE reference, snyk
- https://github.com/kjur/jsrsasign/commit/ee4b013478366cb16cea9a4bdfb218b6077f83b1CVE reference, snyk
- https://access.redhat.com/security/cve/CVE-2026-4599CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2450207CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4599.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:19409CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:19410CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6912CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6720CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6568CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:19375CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6926CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incomplete Comparison with Missing Factors
Incomplete Comparison with Missing Factors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.