CVE-2026-4600
CVE-2026-4600 is a CWE-347 vulnerability in jsrsasign. O3 Security confirms whether CVE-2026-4600 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
jsrsasign: DSA signatures or X.509 certificates can be forged via DSA domain-parameter validation in KJUR.crypto.DSA.setPublic
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
jsrsasignnpmDescription
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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jsrsasign | all versions | 11.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsrsasign. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 pinpoints whether CVE-2026-4600 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
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.
Frequently Asked Questions
Is CVE-2026-4600 in your dependencies?
O3 detects CVE-2026-4600 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.