CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVE-2021-46743
Critical (9.1) in google firebase php-jwt. EPSS 0.9% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 0.9% chance of exploitation in the next 30 days; higher than 60% of CVEs (scores of 2026-11-01)
- CWE
- CWE-843
- Published
- Modified
- Record from
- the NVD, synced
Affected
- google:firebase_php-jwt