CVE-2026-59354 Spring Security OAuth2 Authorization Server: Insufficient validation of Dynamic Client Registration metadata
Attackers with valid tokens can inject malicious metadata causing XSS, privilege escalation, or SSRF in Spring Security OAuth2 Authorization Server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-59354?
CVE-2026-59354 is a critical cross-site scripting vulnerability in VMware by Broadcom Spring Security (OAuth2 Authorization Server module), published on 27 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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).
Weakness: CWE-20
Which versions are affected by CVE-2026-59354?
It affects 1 product.
Products include Vmware Spring Security.
How do I fix CVE-2026-59354?
No fix has been published for CVE-2026-59354 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-59354 being exploited?
There is no known exploitation of CVE-2026-59354 in the wild and no public exploit code.
Other vulnerabilities in VMware by Broadcom Spring Security (OAuth2 Authorization Server module)
- CVE-2014-3527 Authorization Bypass in Spring Security
- CVE-2026-59270 Spring Security embedded UnboundID LDAP server exposes well-known administrative bind DN on all network interfaces
- CVE-2026-22732 Under Some Conditions Spring Security HTTP Headers Are not Written
- CVE-2023-34034 Access Control Bypass in Spring Security
- CVE-2026-47877 Spring Security Authorization Server Default Consent Page is vulnerable to Cross-Site Scripting (XSS)
Sources
Also known as GHSA-j9pv-5342-rrx5.