Vulnerability · Published Aug 27, 2026 · Assigned by vmware

CVE-2026-59354Spring Security OAuth2 Authorization Server: Insufficient validation of Dynamic Client Registration metadata

Critical 9.6

In plain English

A critical-severity improper input validation in Spring Security (OAuth2 Authorization Server module) from VMware by Broadcom. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).

Severity (CVSS 3.1)9.6Critical

Exploit odds (30 days)0.5%top 57.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

In versions of Spring Security's OAuth2 Authorization Server module 7.0.0 through 7.0.4, when Dynamic Client Registration is explicitly enabled, the registration endpoint performs insufficient validation of certain client metadata fields supplied by the registering client. An attacker who possesses a valid Initial Access Token can register a malicious client with crafted metadata, which, depending on server configuration and how the metadata is later rendered or used, may result in Stored Cross-Site Scripting (XSS), Privilege Escalation, or Server-Side Request Forgery (SSRF).

Affected products (as reported)

Vendor	Product	Versions
VMware by Broadcom	Spring Security (OAuth2 Authorization Server module)	7.0.0 – through 7.0.4

Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

References

spring.io vendor-advisory
CVSS v3.1 Calculator technical-description