Vulnerability Report

CVE-2026-5430

CISA KEV Active

Title: JWT authentication bypass via algorithm confusion

Auth Bypass

Proof Of Concept

PoC Available for CVE-2026-5430

CWE Category CWE-347

Published Date Aug 06, 2026

Modified Date Sep 25, 2026

Exploit Status Available

Score 10.0 CVSS v3.1

Exploit Probability (EPSS)

0.58%

Vulnerability Summary

CVE-2026-5430: 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.

Impacted Vendors

wso2 4

Reference Links

https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5328/

CVSS v3.1

Source Entity ed10eef1-636d-4fbe-9993-6890dfa878f8

Severity CRITICAL

10.0

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns