jsrsasign: Division by Zero Allows Invalid JWK Modulus to Cause Deterministic Zero Output in RSA Operations
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.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | jsrsasign | < 11.1.1 | 11.1.1 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-4603
- https://github.com/kjur/jsrsasign/pull/649
- https://github.com/kjur/jsrsasign/commit/dc41d49fac4297e7a737a3ef8ebd0aa9c49ef93f
- https://gist.github.com/Kr0emer/5366b7364c4fbf7e754bc377f321e9f3
- https://github.com/kjur/jsrsasign
- https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371176
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L- Weakness (CWE)
CWE-369- Platform
- npm
- Package
jsrsasign- Disclosed
- 23.03.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-464q-cqxq-xhgr - CC BY 4.0
Vulnerability history: jsrsasign
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 14
- First → latest
- 06.2020 03.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 4
- High 7
- Medium 2
- Low 1
Disclosures per year
- 2020: 4
- 2021: 1
- 2022: 2
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 6
-
jsrsasign: Division by Zero Allows Invalid JWK Modulus to Cause Deterministic Zero Output in RSA Operations this entry
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