CVE-2026-4603
Last modified
CVE-2026-4603 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Versions of the package jsrsasign before 11.1.1 are vulnerable to Division by zero due to the RSASetPublic/KEYUTIL parsing path in ext/rsa.js and the BigInteger.modPowInt reduction logic in ext/jsbn.js. An attacker can force RSA public-key operations (e.g., verify and encryption) to collapse to deterministic zero outputs and hide “invalid key” errors by supplying a JWK whose modulus decodes to zero.. EPSS estimates a 0.10% chance of exploitation in the next 30 days.
Description
Versions of the package jsrsasign before 11.1.1 are vulnerable to Division by zero due to the RSASetPublic/KEYUTIL parsing path in ext/rsa.js and the BigInteger.modPowInt reduction logic in ext/jsbn.js. An attacker can force RSA public-key operations (e.g., verify and encryption) to collapse to deterministic zero outputs and hide “invalid key” errors by supplying a JWK whose modulus decodes to zero.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Kjur | Jsrsasign | < 11.1.1 |
References
- https://gist.github.com/Kr0emer/5366b7364c4fbf7e754bc377f321e9f3Exploit, Mitigation, Third Party Advisory
- https://github.com/kjur/jsrsasign/pull/649Issue Tracking
- https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371176Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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