VULNERABILITY INTELLIGENCE

CVE-2021-46743

CVSS score9.1 CRITICAL
EPSS probability0.92%
CISA KEVNot currently listed
Published2022-03-29
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Description

In Firebase PHP-JWT before 6.0.0, an algorithm-confusion issue (e.g., RS256 / HS256) exists via the kid (aka Key ID) header, when multiple types of keys are loaded in a key ring. This allows an attacker to forge tokens that validate under the incorrect key. NOTE: this provides a straightforward way to use the PHP-JWT library unsafely, but might not be considered a vulnerability in the library itself.

Weakness classification

  • nvd@nist.gov: CWE-843

Primary references