How severe is CVE-2026-4600?

No CVSS score has been assigned to CVE-2026-4600 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-4600?

CVE-2026-4600 affects the following packages: jsrsasign (npm). Ecosystems affected: npm.

How do I fix CVE-2026-4600?

Update jsrsasign to 11.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-4600 is resolved across your whole dependency graph.

How do I detect CVE-2026-4600 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsrsasign, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-4600 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-4600?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-4600 can be triaged on real exposure rather than presence alone.

Is CVE-2026-4600 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-4600 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-4600?

CVE-2026-4600 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 13th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-4600?

CVE-2026-4600 is classified as CWE-347 (CWE-347). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-4600 published, and has it been updated?

CVE-2026-4600 was published on March 23, 2026 and was last updated on September 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-4600 — jsrsasign

Fix: kjur/jsrsasign@37b4c06

CVE-2026-4600 is a CWE-347 vulnerability in jsrsasign. A fix is available for jsrsasign — see the affected versions and patch details below.

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

Also known asGHSA-wvqx-v3f6-w8rh

Published

Mar 23, 2026

Updated

Sep 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-4600.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs13th percentile — riskier than 13% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.

jsrsasignnpm

1.2Mdownloads / week

Description

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`jsrsasign`	all versions	11.1.1`npm install jsrsasign@11.1.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsrsasign, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jsrsasign to 11.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-4600 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-4600 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-4600. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

IMPORTANT. The flaw in jsrsasign allows an attacker to forge Digital Signature Algorithm (DSA) signatures or X.509 certificates by providing malicious domain parameters during validation. This could lead to unauthorized access or data manipulation in affected Red Hat products such as Migration Toolkit for…

Product	Fixed in	Advisory
Migration Toolkit for Virtualization 2.1	`migration-toolkit-virtualization/mtv-console-plugin-rhel9:1779139872`	RHSA-2026:19409
Migration Toolkit for Virtualization 2.9	`migration-toolkit-virtualization/mtv-console-plugin-rhel9:1778927462`	RHSA-2026:19410
Red Hat Quay 3.10	`quay/quay-rhel8:1775169155`	RHSA-2026:6912
Red Hat Quay 3.12	`quay/quay-rhel8:1775253092`	RHSA-2026:6720
Red Hat Quay 3.15	`quay/quay-rhel8:1775169219`	RHSA-2026:6568
Red Hat Quay 3.16	`quay/quay-rhel9:1779204086`	RHSA-2026:19375
Red Hat Quay 3.9	`quay/quay-rhel8:1775169218`	RHSA-2026:6926

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-4600 in your dependencies?

O3 Security finds CVE-2026-4600 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works