# CVE-2026-40991: VMware Spring REST Docs XXE injection in webtestclient and restassured

Source: https://junglewise.ai/threats/cve-2026-40991-vmware-spring-rest-docs-xxe-injection-in-webtestclient-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-10. Updated: 2026-08-12  
License: CC BY 4.0 with a link back

CVE-2026-40991 · Severity: medium · CVSS 5.9 · Published 2026-06-10

Spring REST Docs is a library used by developers to automatically generate documentation for web APIs. A security vulnerability exists where the tool improperly handles XML data when documenting remote services. If a developer is tricked into documenting a malicious API or if a documented API is compromised, an attacker could potentially read sensitive files from the developer's machine or the build server during the documentation process.

Vendors: [Maven](https://junglewise.ai/threats/vendors/maven), [Spring](https://junglewise.ai/threats/vendors/spring), [VMware](https://junglewise.ai/threats/vendors/vmware).

## Quick answers

**Is CVE-2026-40991 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-40991 being exploited in the wild.

**How severe is CVE-2026-40991?** Medium severity, with a CVSS score of 5.9, published 10 June 2026.

**Which products and versions are affected?** org.springframework.restdocs:spring-restdocs-restassured (Maven) ECOSYSTEM:introduced=4.0.0,fixed=4.0.1; org.springframework.restdocs:spring-restdocs-webtestclient (Maven) ECOSYSTEM:introduced=4.0.0,fixed=4.0.1; Spring REST Docs 4.0.0, 3.0.0 - 3.0.5, 2.0.0.RELEASE - 2.0.8.RELEASE; VMware Spring REST Docs 4.0.0, 3.0.0 through 3.0.5, 2.0.0.RELEASE through 2.0.8.RELEASE.

**Is there a fix for CVE-2026-40991?** Yes. org.springframework.restdocs:spring-restdocs-restassured (Maven): upgrade to 4.0.1 or later; org.springframework.restdocs:spring-restdocs-webtestclient (Maven): upgrade to 4.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-40991 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-40991?** Check whether you run org.springframework.restdocs:spring-restdocs-restassured (Maven), org.springframework.restdocs:spring-restdocs-webtestclient (Maven), Spring REST Docs or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.springframework.restdocs:spring-restdocs-restassured (Maven): upgrade to 4.0.1 or later

  ```sh
  # set org.springframework.restdocs:spring-restdocs-restassured to 4.0.1 in your pom.xml or build.gradle
  ```

- org.springframework.restdocs:spring-restdocs-webtestclient (Maven): upgrade to 4.0.1 or later

  ```sh
  # set org.springframework.restdocs:spring-restdocs-webtestclient to 4.0.1 in your pom.xml or build.gradle
  ```


## Technical details

Spring REST Docs (specifically the spring-restdocs-webtestclient and spring-restdocs-restassured modules) is vulnerable to XML External Entity (XXE) injection (CWE-611). The vulnerability occurs when the library processes XML responses from a remote API to generate documentation. An attacker who controls the target API can provide a malicious XML payload containing external entity references. When the documentation-generating tests are executed, the XML parser may resolve these entities, allowing the attacker to perform unauthorized data retrieval (such as local file disclosure) or server-side request forgery (SSRF). The attack requires the user to execute tests against a malicious or compromised endpoint. The issue is addressed in versions 3.0.6 and 4.0.1.

## Affected products

- Spring Spring REST Docs 4.0.0, 3.0.0 - 3.0.5, 2.0.0.RELEASE - 2.0.8.RELEASE

## Identifiers

- CVE-2026-40991
- GHSA-6rpq-6vv2-5222

## Timeline

- 2026-06-09: patched: Versions 3.0.6 and 4.0.1 released
- 2026-06-10: disclosed: Initial advisory publication
- 2026-08-12: advisory: GitHub Advisory updated

## References

- [https://spring.io/security/cve-2026-40991](https://spring.io/security/cve-2026-40991)
- [https://github.com/spring-projects/spring-restdocs/releases/tag/v3.0.6](https://github.com/spring-projects/spring-restdocs/releases/tag/v3.0.6)
- [https://github.com/spring-projects/spring-restdocs/releases/tag/v4.0.1](https://github.com/spring-projects/spring-restdocs/releases/tag/v4.0.1)