Authentication Bypass via JWT Algorithm Mismatch in Multiple WSO2 Products Allows Account Takeover
At a glance
Severity
CRITICAL 10.0
Exploitation
Known exploited (CISA KEV) · added 2026-09-24 Exploited per ENISA since 2026-09-24
EPSS
EPSS 22.39 % · percentile 98 (2026-10-28)
State
PUBLISHED
Published
Updated
Assigner
WSO2
NVD status
Analyzed
Description
The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported. This allows an attacker to craft a JWT with an unsupported algorithm, which is then incorrectly validated, leading to unauthorized access.
Successful exploitation of this vulnerability may result in unauthorized access to the system, including the potential compromise of administrative accounts and full account takeover. The CVSS score is adjusted to 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) in single-tenant deployments, reflecting that the impact is contained within a single security authority boundary.