CVE-2026-40996: Spring Web Services Inbound WS-Security Allows RSA PKCS#1 Vulnerability

MODERATE
Advisory Identifier: GHSA-p7qj-2q5w-f9r7
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CVSS 4.8
CWE-327
Published
Advisory Summary

CVE-2026-40996 is a MODERATE (CVSS 4.8) inbound ws-security allows rsa pkcs#1 vulnerability (CWE-327: Use of a Broken or Risky Cryptographic Algorithm) affecting Spring Web Services libraries in the Maven ecosystem. The issue involves inbound ws-security allows rsa pkcs#1 v1.5 key transport by default. Remediation is available by upgrading affected packages to version 5.0.2, 4.1.4.

CVE-2026-40996 at a Glance

CVE Identifier CVE-2026-40996
GHSA Identifier GHSA-p7qj-2q5w-f9r7
Severity MODERATE
CVSS v3.1 Base Score 4.8
CWE Classification CWE-327: Use of a Broken or Risky Cryptographic Algorithm
Affected Product Spring Web Services
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.8

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

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

How to Fix CVE-2026-40996

To remediate this vulnerability, upgrade all affected Spring Web Services 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.ws:spring-ws-security fixed: 5.0.2 
<dependency>
    <groupId>org.springframework.ws</groupId>
    <artifactId>spring-ws-security</artifactId>
    <version>5.0.2</version>
</dependency>
org.springframework.ws:spring-ws-security fixed: 4.1.4 
<dependency>
    <groupId>org.springframework.ws</groupId>
    <artifactId>spring-ws-security</artifactId>
    <version>4.1.4</version>
</dependency>
org.springframework.ws:spring-ws-security fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.ws</groupId>
    <artifactId>spring-ws-security</artifactId>
    <version>Latest secure release</version>
</dependency>
org.springframework.ws:spring-ws-security fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.ws</groupId>
    <artifactId>spring-ws-security</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.ws

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-40996, inspect your build dependencies using the Maven Dependency Plugin:

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

Analyze the terminal output to locate any version of Spring Web Services in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.0.2), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.springframework.ws 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-327: Use of a Broken or Risky Cryptographic Algorithm, where the product uses a broken or risky cryptographic algorithm or protocol. In Spring Web Services, 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

Wss4jSecurityInterceptor defaulted allowRSA15KeyTransportAlgorithm to true, overriding Apache WSS4J's safer default for validation RequestData. Inbound WS-Security decryption could therefore accept RSA PKCS#1 v1.5 (rsa-1_5) encrypted key material unless operators explicitly reconfigured the flag. Affected versions: Spring Web Services 5.0.0 through 5.0.1; 4.1.0 through 4.1.3; 4.0.0 through 4.0.18; 3.1.0 through 3.1.8.

CVE-2026-40996 Affected Spring Web Services Versions

4 component(s)
Fixed Versions:
5.0.24.1.4
Product / Package Ecosystem Affected Versions Fixed Version
org.springframework.ws:spring-ws-security
maven/org.springframework.ws/spring-ws-security
Maven
≥ 5.0.0
< 5.0.2
5.0.2
org.springframework.ws:spring-ws-security
maven/org.springframework.ws/spring-ws-security
Maven
≥ 4.1.0
< 4.1.4
4.1.4
org.springframework.ws:spring-ws-security
maven/org.springframework.ws/spring-ws-security
Maven
≥ 4.0.0
≤ 4.0.18
org.springframework.ws:spring-ws-security
maven/org.springframework.ws/spring-ws-security
Maven
≥ 3.1.0
≤ 3.1.8

References

NVD — CVE-2026-40996 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40996
Spring Web Services Source Repository REPOSITORY
https://github.com/spring-projects/spring-ws
Spring Web Services Security Information SECURITY
https://spring.io/security/cve-2026-40996

Frequently Asked Questions

What is CVE-2026-40996?
CVE-2026-40996 is a security vulnerability in Spring Web Services involving Inbound WS-Security allows RSA PKCS#1 v1.5 key transport by default under CWE-327: Use of a Broken or Risky Cryptographic Algorithm.
Which Spring Web Services versions are affected?
Affected versions include releases prior to 5.0.2, 4.1.4 across affected packages: org.springframework.ws:spring-ws-security.
What version fixes CVE-2026-40996?
Upgrading to 5.0.2, 4.1.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is spring-ws-security affected?
Yes, org.springframework.ws:spring-ws-security is affected in releases prior to 5.0.2, 4.1.4, Latest secure release. Upgrade your dependency to 5.0.2, 4.1.4, Latest secure release or later.
What is the CVSS score of CVE-2026-40996?
CVE-2026-40996 has a CVSS v3.1 base score of 4.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2026-40996?
CVE-2026-40996 is classified under CWE-327: Use of a Broken or Risky Cryptographic Algorithm (The product uses a broken or risky cryptographic algorithm or protocol.).
How can I check Maven dependencies for CVE-2026-40996?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.springframework.ws'. 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-p7qj-2q5w-f9r7",
  "modified" : "2026-08-21T19:12:53Z",
  "published" : "2026-06-11T09:31:56Z",
  "aliases" : [ "CVE-2026-40996" ],
  "summary" : "Spring Web Services: Inbound WS-Security allows RSA PKCS#1 v1.5 key transport by default",
  "details" : "Wss4jSecurityInterceptor defaulted allowRSA15KeyTransportAlgorithm to true, overriding Apache WSS4J's safer default for validation RequestData. Inbound WS-Security decryption could therefore accept RSA PKCS#1 v1.5 (rsa-1_5) encrypted key material unless operators explicitly reconfigured the flag.\n\nAffected versions:\nSpring Web Services 5.0.0 through 5.0.1; 4.1.0 through 4.1.3; 4.0.0 through 4.0.18; 3.1.0 through 3.1.8.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.ws:spring-ws-security"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0"
      }, {
        "fixed" : "5.0.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.0.1"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.ws:spring-ws-security"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.1.0"
      }, {
        "fixed" : "4.1.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.1.3"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.ws:spring-ws-security"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "last_affected" : "4.0.18"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.ws:spring-ws-security"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.1.0"
      }, {
        "last_affected" : "3.1.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40996"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/spring-projects/spring-ws"
  }, {
    "type" : "WEB",
    "url" : "https://spring.io/security/cve-2026-40996"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-327" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-21T19:12:53Z",
    "nvd_published_at" : "2026-06-11T07:16:27Z"
  }
}