CVE-2026-5430
CriticalExploitedPublic exploitThe JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported.
Published Aug 6, 2026 · Updated Sep 25, 2026 · Also known as EUVD-2026-53822, GHSA-j7vh-5w8q-4m4x
Key Facts
Patch immediately- CVE-2026-5430 is a critical-severity vulnerability (CVSS 10.0 v3.1) affecting API Control Plane (Wso2), API Manager (Wso2), Traffic Manager (Wso2) and 3 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 15, 2026. Public exploit code is available.
- EPSS estimates a 0.6% probability of exploitation in the next 30 days.
- Fixed versions are available, including org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util 9.20.74.401, org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util 9.28.116.417, org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util 9.29.120.236.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
0.6%
Higher than 47.0% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-5430 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Sep 24, 2026 | Sep 27, 2026 | Not reported |
| Industry KEV feed | Sep 15, 2026 | Sep 27, 2026 | Not reported |
| CIRCL KEV | Sep 16, 2026 | Sep 27, 2026 | Not reported |
| ENISA EUVD | Sep 24, 2026 | n/a | Not reported |
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Affected Products
14 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| API Control PlaneWso2 | >= 4.5.0 | 4.5.0.58 |
| API ManagerWso2 | >= 4.1.0 | 4.1.0.257 |
| Traffic ManagerWso2 | >= 4.5.0 | 4.5.0.56 |
| Universal GatewayWso2 | >= 4.5.0 | 4.5.0.57 |
| org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util | >= 9.20.74 | 9.20.74.401 |
Patched Releases
org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util
9.20.74.401, 9.28.116.417, 9.29.120.236, 9.30.67.167, 9.31.86.158, 9.32.147.59
API Control Plane
4.5.0.58, 4.6.0.22
API Manager
4.1.0.257, 4.2.0.197, 4.3.0.108, 4.4.0.72, 4.5.0.57, 4.6.0.21
WSO2 Carbon API Manager Rest API Utility
9.20.74.401, 9.28.116.417, 9.29.120.236, 9.30.67.167, 9.31.86.158, 9.32.147.59
Traffic Manager
4.5.0.56, 4.6.0.21
Universal Gateway
4.5.0.57, 4.6.0.21
Timeline
Publicly disclosed
Aug 6, 2026
Added to Industry KEV feed
Sep 15, 2026
Added to CIRCL KEV
Sep 16, 2026
Added to CISA KEV
Sep 24, 2026
Added to ENISA EUVD
Sep 24, 2026
Last updated
Sep 25, 2026
Weakness Type
- CWE-347 Improper Verification of Cryptographic Signature
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- otherhttps://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5328/
- otherhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-5430
FAQ
Common Questions.
The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported.
Affected: API Control Plane (Wso2) versions >= 4.5.0; API Manager (Wso2) versions >= 4.1.0; Traffic Manager (Wso2) versions >= 4.5.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 15, 2026.
Yes. It was added on Sep 24, 2026 with a federal remediation due date of Sep 27, 2026.
Public exploit code is available.
Fixed versions are available, including org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util 9.20.74.401, org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util 9.28.116.417, org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util 9.29.120.236.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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