CVE-2026-84185

Description

A flaw was found in the jwcrypto library, which is used for implementing Javascript Object Signing and Encryption (JOSE) standards. The issue occurs when the library verifies a General JSON Serialization JWS using a set of keys. Due to a coding error, the library fails to correctly identify the specific key ID (kid) and may instead accept a signature made by any valid key in the set. This can allow an attacker with a valid key to bypass authorization checks in applications that rely on the key ID to identify specific tenants or users.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.9CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N

EPSS Trends

Current EPSS score: 0.09%• Percentile: 0%

Techniques & Countermeasures

• CWE-347•Improper Verification of Cryptographic Signature

  The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Affected Systems

• debian•python-jwcrypto

  all | all | all

• ubuntu•python-jwcrypto

  all | all | all | all | all | all

References (5)

• https://access.redhat.com/security/cve/CVE-2026-84185
• https://bugzilla.redhat.com/show_bug.cgi?id=2526729
• https://ubuntu.com/security/CVE-2026-84185
• https://www.cve.org/CVERecord?id=CVE-2026-84185
• https://security-tracker.debian.org/tracker/CVE-2026-84185