Vulnerability · Published Jun 9, 2026 · Assigned by vmware
CVE-2026-40988Unbounded DEFLATE Inflation in SAML 2.0 Service Provider
High 7.5
In plain English
A high-severity uncontrolled resource consumption in Spring Security from Spring. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.springframework.security:spring-security-saml2-service-provider | 7.0.6 | GHSA-m69x-pw9p-7j3q |
| Maven | org.springframework.security:spring-security-saml2-service-provider | 6.5.11 | GHSA-m69x-pw9p-7j3q |
| Maven | org.springframework.security:spring-security-saml2-service-provider | no fix listed | GHSA-m69x-pw9p-7j3q |
| Maven | org.springframework.security:spring-security-saml2-service-provider | no fix listed | GHSA-m69x-pw9p-7j3q |
| Maven | org.springframework.security:spring-security-saml2-service-provider | no fix listed | GHSA-m69x-pw9p-7j3q |
| Maven | org.springframework.security:spring-security-saml2-service-provider | no fix listed | GHSA-m69x-pw9p-7j3q |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Spring | Spring Security | 5.7.0 – before 5.7.245.8.0 – before 5.8.266.3.0 – before 6.3.176.4.0 – before 6.4.176.5.0 – before 6.5.10.27.0.0 – before 7.0.5.1 |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H