CRITICAL CISA KEV

CVE-2026-5430

CVSS v3

CRITICAL

EPSS Score

0.2 %

exploit probability

CISA KEV

Yes

known exploited

Exploitation

—

SSVC status

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:

CISA Known Exploited Vulnerability

Date Added: 2026-09-24
Patch Due Date: 2026-09-27
Ransomware Use: Unknown

Technical details

CVSS v3 Vector: 3.1
Published: 2026-08-06
Last Modified: 2026-08-06

Frequently asked questions

What is CVE-2026-5430?

Is CVE-2026-5430 actively exploited?

Yes. CVE-2026-5430 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-09-27.

What is the CVSS score for CVE-2026-5430?

CVE-2026-5430 has a CVSS v3 base score of 10 (CRITICAL severity), with vector string 3.1.

Is CVE-2026-5430 affecting your environment?

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