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WSO2 · Multiple Products

CVE-2026-5430

Authentication Bypass via JWT Algorithm Mismatch in Multiple WSO2 Products Allows Account Takeover

Exploited in attacks Critical 10.0 Attack chance: 22%
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What it is

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.

CISA: WSO2 API Control Plane, API Manager, Traffic Manager & Universal Gateway contain a path traversal vulnerability that could allow for unrestricted file upload and lead to remote code execution.

What to do

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.

Deadline for US federal agencies: September 27, 2026

Added to the CISA list
September 24, 2026
Published
August 6, 2026
Severity
Critical 10.0 CVSS 3.1
Chance of attacks in the next 30 days (EPSS)
22% in the top 2.3% of all known vulnerabilities
Weakness
CWE-347
More details
NVD · CVE.org · CISA

More exploited flaws from WSO2

AddedVulnerabilityProductSeverityAttack chance
Apr 25, 2022Unrestrictive Upload of FileCVE-2022-29464used by ransomwareMultiple ProductsCritical 9.8>99.9%

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Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.