Vulnerability Report

CVE-2026-40988

Title: Denial of Service in Spring Security SAML 2.0

DoS

Proof Of Concept

No public PoC currently indexed for CVE-2026-40988.

CWE Category CWE-400

Published Date Jun 10, 2026

Modified Date Jul 23, 2026

Exploit Status Not Found

Score 7.5 CVSS v3.1

Exploit Probability (EPSS)

0.33%

Vulnerability Summary

CVE-2026-40988: An application using spring-security-saml2-service-provider and the REDIRECT binding for SAML 2.0 Login or Logout may be vulnerable to a denial of service by way of an unbounded writer that inflates the compressed SAML payload into memory. Affected versions: Spring Security 5.7.0 through 5.7.23; 5.8.0 through 5.8.25; 6.3.0 through 6.3.16; 6.4.0 through 6.4.16; 6.5.0 through 6.5.10; 7.0.0 through 7.0.5.

Impacted Vendors

vmware 1

webauthn4j 1

Reference Links

https://spring.io/security/cve-2026-40988

CVSS v3.1

Source Entity [email protected]

Severity HIGH

7.5

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns