# CVE-2026-40991: XML External Entity (XXE) injection when documenting untrusted XML content > Attackers can exploit XXE injection in Spring REST Docs when documenting malicious remote APIs, potentially exposing sensitive data or causing denial of service. - **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 9 Jun 2026 - **Updated:** 27 Jun 2026 - **Also known as:** CLSA-2026-1793192311, GHSA-6rpq-6vv2-5222, ROOT-APP-MAVEN-CVE-2026-40991 ## What is CVE-2026-40991? CVE-2026-40991 is a medium-severity vulnerability in Spring REST Docs, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description When using spring-restdocs-webtestclient or spring-restdocs-restassured to document a remote API accessed over HTTP, an attacker who compromises the API or tricks the user into documenting a malicious API can perform an XXE injection attack when the documentation-generating tests are next executed. Affected versions: Spring REST Docs 4.0.0; 3.0.0 through 3.0.5; 2.0.0.RELEASE through 2.0.8.RELEASE. Weakness: CWE-611 (Improper Restriction of XML External Entity Reference) ## Which versions are affected by CVE-2026-40991? 12 open source packages ship an affected version, including org.springframework.restdocs:spring-restdocs-restassured and org.springframework.restdocs:spring-restdocs-webtestclient. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `org.springframework.restdocs:spring-restdocs-restassured` | Maven | All versions to 2.0.8.RELEASE | None | | `org.springframework.restdocs:spring-restdocs-restassured` | Maven | All versions to 2.0.8.RELEASE | None | | `org.springframework.restdocs:spring-restdocs-restassured` | Maven | From 3.0.0 | 3.0.6 | | `org.springframework.restdocs:spring-restdocs-restassured` | Maven | From 3.0.0 | 3.0.6 | | `org.springframework.restdocs:spring-restdocs-restassured` | Maven | From 4.0.0 | 4.0.1 | | `org.springframework.restdocs:spring-restdocs-restassured` | Maven | From 4.0.0 | 4.0.1 | | `org.springframework.restdocs:spring-restdocs-webtestclient` | Maven | All versions to 2.0.8.RELEASE | None | | `org.springframework.restdocs:spring-restdocs-webtestclient` | Maven | All versions to 2.0.8.RELEASE | None | | `org.springframework.restdocs:spring-restdocs-webtestclient` | Maven | From 3.0.0 | 3.0.6 | | `org.springframework.restdocs:spring-restdocs-webtestclient` | Maven | From 3.0.0 | 3.0.6 | | `org.springframework.restdocs:spring-restdocs-webtestclient` | Maven | From 4.0.0 | 4.0.1 | | `org.springframework.restdocs:spring-restdocs-webtestclient` | Maven | From 4.0.0 | 4.0.1 | Products: Broadcom Spring Rest Docs. ## How do I fix CVE-2026-40991? Upgrade org.springframework.restdocs:spring-restdocs-restassured to a fixed version for your release line: 3.0.6 or 4.0.1. ## Is CVE-2026-40991 being exploited? There is no known exploitation of CVE-2026-40991 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-40991 and fix it if it is affected. What it is: CVE-2026-40991 is a medium-severity vulnerability in Spring REST Docs, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2026-40991 in the wild and no public exploit code. Affected packages and fixed versions: - org.springframework.restdocs:spring-restdocs-restassured (Maven): affected all versions up to 2.0.8.RELEASE; no fix listed - org.springframework.restdocs:spring-restdocs-restassured (Maven): affected all versions up to 2.0.8.RELEASE; no fix listed - org.springframework.restdocs:spring-restdocs-restassured (Maven): affected from 3.0.0; fixed in 3.0.6 - org.springframework.restdocs:spring-restdocs-restassured (Maven): affected from 3.0.0; fixed in 3.0.6 - org.springframework.restdocs:spring-restdocs-restassured (Maven): affected from 4.0.0; fixed in 4.0.1 - org.springframework.restdocs:spring-restdocs-restassured (Maven): affected from 4.0.0; fixed in 4.0.1 - org.springframework.restdocs:spring-restdocs-webtestclient (Maven): affected all versions up to 2.0.8.RELEASE; no fix listed - org.springframework.restdocs:spring-restdocs-webtestclient (Maven): affected all versions up to 2.0.8.RELEASE; no fix listed - org.springframework.restdocs:spring-restdocs-webtestclient (Maven): affected from 3.0.0; fixed in 3.0.6 - org.springframework.restdocs:spring-restdocs-webtestclient (Maven): affected from 3.0.0; fixed in 3.0.6 - org.springframework.restdocs:spring-restdocs-webtestclient (Maven): affected from 4.0.0; fixed in 4.0.1 - org.springframework.restdocs:spring-restdocs-webtestclient (Maven): affected from 4.0.0; fixed in 4.0.1 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-40991/ (Markdown: https://insights.sbomify.com/CVE-2026-40991/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40991 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40991 - OSV: https://osv.dev/vulnerability/CVE-2026-40991 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-40991/ Summaries are generated and may contain mistakes; the official description above is the record.