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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
WSO2 WSO2 Universal Gateway unaffected
Version Status Constraints
4.5.0 affected < 4.5.0.57
4.6.0 affected < 4.6.0.21
WSO2 WSO2 Traffic Manager unaffected
Version Status Constraints
4.5.0 affected < 4.5.0.56
4.6.0 affected < 4.6.0.21
WSO2 WSO2 API Control Plane unaffected
Version Status Constraints
4.5.0 affected < 4.5.0.58
4.6.0 affected < 4.6.0.22
WSO2 WSO2 API Manager unaffected
Version Status Constraints
0 unknown < 4.1.0
4.1.0 affected < 4.1.0.257
4.2.0 affected < 4.2.0.197
4.3.0 affected < 4.3.0.108
4.4.0 affected < 4.4.0.72
4.5.0 affected < 4.5.0.57
4.6.0 affected < 4.6.0.21
WSO2 WSO2 Carbon API Manager Rest API Utility unknown
Version Status Constraints
9.20.74 affected < 9.20.74.401
9.28.116 affected < 9.28.116.417
9.29.120 affected < 9.29.120.236
9.30.67 affected < 9.30.67.167
9.31.86 affected < 9.31.86.158
9.32.147 affected < 9.32.147.59
9.33.106 unaffected ≤ *

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

Follow the instructions given on https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5328/#solution https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5328/#solution

Workaround

No workaround given by the vendor.

References
Link Providers
https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5328/ cve-icon
History

Thu, 06 Aug 2026 08:15:00 +0000

Type Values Removed Values Added
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.
Title Authentication Bypass via JWT Algorithm Mismatch in Multiple WSO2 Products Allows Account Takeover
Weaknesses CWE-347
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: WSO2

Published:

Updated: 2026-08-06T07:33:28.156Z

Reserved: 2026-04-02T16:11:32.536Z

Link: CVE-2026-5430

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses