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).
Published: 2026-08-27
Score: 9.6 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability resides in the Dynamic Client Registration endpoint of Spring Security's OAuth2 Authorization Server module. When the feature is enabled, the server accepts client‑supplied metadata without performing sufficient validation. An attacker possessing a valid Initial Access Token can register a client that contains malicious content in its metadata. Depending on how that data is later rendered or processed, the flaw can lead to Stored Cross‑Site Scripting, Privilege Escalation, or Server‑Side Request Forgery.

Affected Systems

The affected product is VMware by Broadcom's Spring Security OAuth2 Authorization Server module, versions 7.0.0 through 7.0.4. The issue occurs only when Dynamic Client Registration is explicitly enabled, and only for instances that expose the registration endpoint.

Risk and Exploitability

The CVSS score of 6.1 indicates moderate severity. Exploitation requires a valid Initial Access Token, which may originate from a separate compromise, and includes no user interaction. No EPSS score is currently published for this vulnerability, and it is not listed in CISA's KEV catalog. Attacks would proceed by sending a crafted registration request to the endpoint; if the metadata is rendered into HTML or used in server‑side logic, the attacker could execute persistent XSS, elevate privileges, or force internal requests.

Generated by OpenCVE AI on August 27, 2026 at 10:55 UTC.

Remediation

Vendor Solution

Upgrade to Spring Security 7.0.5 or later.


OpenCVE Recommended Actions

  • Upgrade to Spring Security 7.0.5 or later
  • If upgrading immediately is not possible, disable Dynamic Client Registration or restrict it to trusted clients
  • Validate or sanitize all client‑supplied metadata before rendering or using it in server‑side logic

Generated by OpenCVE AI on August 27, 2026 at 10:55 UTC.

Tracking

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Advisories

No advisories yet.

History

Thu, 27 Aug 2026 13:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV3_1

{'score': 9.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N'}


Thu, 27 Aug 2026 09:30:00 +0000

Type Values Removed Values Added
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).
Title Spring Security OAuth2 Authorization Server: Insufficient validation of Dynamic Client Registration metadata
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}


Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: vmware

Published:

Updated: 2026-08-27T09:27:56.969Z

Reserved: 2026-07-04T18:14:46.171Z

Link: CVE-2026-59354

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-27T10:16:36.063

Modified: 2026-08-27T13:18:27.513

Link: CVE-2026-59354

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-27T11:00:06Z

Weaknesses
  • CWE-20

    Improper Input Validation