CVE-2026-4603

jsrsasign: jsrsasign: Cryptographic operations impacted by division by zero via malicious JSON Web Key

Published Mar 23, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-464q-cqxq-xhgr jsrsasign: Division by Zero Allows Invalid JWK Modulus to Cause Deterministic Zero Output in RSA Operations
History
Type Values Removed Values Added
First Time appeared Jsrsasign Project
Jsrsasign Project jsrsasign
CPEs cpe:2.3:a:jsrsasign_project:jsrsasign:*:*:*:*:*:node.js:*:*
Vendors & Products Jsrsasign Project
Jsrsasign Project jsrsasign
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title jsrsasign: jsrsasign: Cryptographic operations impacted by division by zero via malicious JSON Web Key
References
Metrics threat_severity

None

threat_severity

Moderate

Type Values Removed Values Added
First Time appeared Kjur
Kjur jsrsasign
Vendors & Products Kjur
Kjur jsrsasign
Type Values Removed Values Added
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.
Weaknesses CWE-369
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
snyk
Published
Updated
Mar 23, 2026, 2:42 PM
Reserved
Mar 22, 2026, 4:26 PM
Status
Analyzed
Published
Mar 23, 2026, 6:16 AM
Modified
Jun 22, 2026, 3:18 AM
Severity
Moderate
Public date
Mar 23, 2026, 5:00 AM