CVE-2026-40988

Unbounded DEFLATE Inflation in SAML 2.0 Service Provider

State: Published
Severity: 7.5 High
Published: Jun 9, 2026
Updated: Jun 27, 2026
Reserved: Apr 16, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	vmware

Weaknesses

CWE-400 Uncontrolled Resource Consumption

Affected Products

Product	Versions
Spring SecuritySpring	5.7.0 to before 5.7.24Affected 5.8.0 to before 5.8.26Affected 6.3.0 to before 6.3.17Affected 6.4.0 to before 6.4.17Affected 6.5.0 to before 6.5.10.2Affected 7.0.0 to before 7.0.5.1Affected

References

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

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.