Input validation error in Spring Security - CVE-2026-59354
Published: August 31, 2026
Vulnerability identifier: #VU146416
CSH Severity: Medium
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-59354
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to escalate privileges, perform server-side request forgery, or conduct stored cross-site scripting attacks.
The vulnerability exists due to insufficient validation of client metadata fields in the dynamic client registration endpoints when processing crafted client metadata during dynamic client registration. A remote user can register a malicious client with crafted metadata to escalate privileges, perform server-side request forgery, or conduct stored cross-site scripting attacks.
The issue is only exposed when dynamic client registration is explicitly enabled and exploitation requires a valid Initial Access Token.
Affected software
Spring Security
How to mitigate CVE-2026-59354
Install security update from vendor's website.
Spring Security - update to 7.0.5