CVE-2026-40988: Spring Framework Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-m69x-pw9p-7j3q
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CVSS 7.5
CWE-400
Published
Advisory Summary

CVE-2026-40988 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Spring Framework libraries in the Maven ecosystem. The issue involves unbounded writer inflates the compressed saml payload into memory (dos). Remediation is available by upgrading affected packages to version 7.0.6, 6.5.11.

CVE-2026-40988 at a Glance

CVE Identifier CVE-2026-40988
GHSA Identifier GHSA-m69x-pw9p-7j3q
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Spring Framework
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-40988

To remediate this vulnerability, upgrade all affected Spring Framework dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.springframework.security:spring-security-saml2-service-provider fixed: 7.0.6 
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-saml2-service-provider</artifactId>
    <version>7.0.6</version>
</dependency>
org.springframework.security:spring-security-saml2-service-provider fixed: 6.5.11 
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-saml2-service-provider</artifactId>
    <version>6.5.11</version>
</dependency>
org.springframework.security:spring-security-saml2-service-provider fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-saml2-service-provider</artifactId>
    <version>Latest secure release</version>
</dependency>
org.springframework.security:spring-security-saml2-service-provider fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-saml2-service-provider</artifactId>
    <version>Latest secure release</version>
</dependency>
org.springframework.security:spring-security-saml2-service-provider fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-saml2-service-provider</artifactId>
    <version>Latest secure release</version>
</dependency>
org.springframework.security:spring-security-saml2-service-provider fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-saml2-service-provider</artifactId>
    <version>Latest secure release</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.springframework.security

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-40988, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.springframework.security

Analyze the terminal output to locate any version of Spring Framework in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.0.6), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.springframework.security command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Spring Framework, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-40988 Affected Spring Framework Versions

6 component(s)
Fixed Versions:
7.0.66.5.11
Product / Package Ecosystem Affected Versions Fixed Version
org.springframework.security:spring-security-saml2-service-provider
maven/org.springframework.security/spring-security-saml2-service-provider
Maven
≥ 7.0.0
< 7.0.6
7.0.6
org.springframework.security:spring-security-saml2-service-provider
maven/org.springframework.security/spring-security-saml2-service-provider
Maven
≥ 6.5.0
< 6.5.11
6.5.11
org.springframework.security:spring-security-saml2-service-provider
maven/org.springframework.security/spring-security-saml2-service-provider
Maven
≥ 6.4.0
≤ 6.4.16
org.springframework.security:spring-security-saml2-service-provider
maven/org.springframework.security/spring-security-saml2-service-provider
Maven
≥ 6.3.0
≤ 6.3.16
org.springframework.security:spring-security-saml2-service-provider
maven/org.springframework.security/spring-security-saml2-service-provider
Maven
≥ 5.8.0
≤ 5.8.25
org.springframework.security:spring-security-saml2-service-provider
maven/org.springframework.security/spring-security-saml2-service-provider
Maven
≤ 5.7.23

References

NVD — CVE-2026-40988 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40988
Spring Framework Source Repository REPOSITORY
https://github.com/spring-projects/spring-security
Spring Framework Release RELEASE
https://github.com/spring-projects/spring-security/releases/tag/6.5.11
Spring Framework Release RELEASE
https://github.com/spring-projects/spring-security/releases/tag/7.0.6
Spring Framework Security Information SECURITY
https://spring.io/security/cve-2026-40988

Frequently Asked Questions

What is CVE-2026-40988?
CVE-2026-40988 is a security vulnerability in Spring Framework involving Unbounded writer inflates the compressed SAML payload into memory (DoS) under CWE-400: Uncontrolled Resource Consumption.
Which Spring Framework versions are affected?
Affected versions include releases prior to 7.0.6, 6.5.11 across affected packages: org.springframework.security:spring-security-saml2-service-provider.
What version fixes CVE-2026-40988?
Upgrading to 7.0.6, 6.5.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is spring-security-saml2-service-provider affected?
Yes, org.springframework.security:spring-security-saml2-service-provider is affected in releases prior to 7.0.6, 6.5.11, Latest secure release. Upgrade your dependency to 7.0.6, 6.5.11, Latest secure release or later.
What is the CVSS score of CVE-2026-40988?
CVE-2026-40988 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-40988?
CVE-2026-40988 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check Maven dependencies for CVE-2026-40988?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.springframework.security'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m69x-pw9p-7j3q",
  "modified" : "2026-08-12T15:40:10Z",
  "published" : "2026-06-10T00:31:51Z",
  "aliases" : [ "CVE-2026-40988" ],
  "summary" : "Spring Security SAML2 Service Provider: Unbounded writer inflates the compressed SAML payload into memory (DoS)",
  "details" : "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.\n\nAffected versions:\nSpring 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.security:spring-security-saml2-service-provider"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.0.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 7.0.5"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.security:spring-security-saml2-service-provider"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.5.0"
      }, {
        "fixed" : "6.5.11"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.5.10"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.security:spring-security-saml2-service-provider"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.4.0"
      }, {
        "last_affected" : "6.4.16"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.security:spring-security-saml2-service-provider"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.3.0"
      }, {
        "last_affected" : "6.3.16"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.security:spring-security-saml2-service-provider"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.8.0"
      }, {
        "last_affected" : "5.8.25"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.security:spring-security-saml2-service-provider"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "5.7.23"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40988"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/spring-projects/spring-security"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/spring-projects/spring-security/releases/tag/6.5.11"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/spring-projects/spring-security/releases/tag/7.0.6"
  }, {
    "type" : "WEB",
    "url" : "https://spring.io/security/cve-2026-40988"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-12T15:40:10Z",
    "nvd_published_at" : "2026-06-10T00:16:49Z"
  }
}