Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-27938 is a high-severity OS Command Injection (CWE-78) vulnerability. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 47% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27938 is an OS command injection vulnerability (CWE-78) in the GitHub Actions workflow file `release.yml` within the `wp-graphql/wp-graphql` repository. WPGraphQL is a plugin that provides a GraphQL API for WordPress sites. The issue affects versions prior to 2.9.1, where the workflow directly incorporates `${{ github.event.pull_request.body }}` into a `run:` shell block without sanitization.
The vulnerability can be exploited by an attacker with low privileges (PR:L) who submits a pull request from the `develop` branch to `master` containing malicious payload in the PR body. Exploitation requires a reviewer to merge the pull request (UI:R), at which point the PR body is injected verbatim into a shell command executed on the GitHub Actions runner. Successful exploitation enables arbitrary command execution on the runner, achieving high confidentiality and integrity impacts with a changed scope (CVSS 7.7).
Version 2.9.1 of WPGraphQL resolves the vulnerability. Additional details are available in the GitHub security advisory at https://github.com/wp-graphql/wp-graphql/security/advisories/GHSA-4q9f-mjxf-rx7x and the fixing commit at https://github.com/wp-graphql/wp-graphql/commit/de0c2d590593f1099546ad517106e454a498bc58.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8803
Vulnerability Data
WPGraphQL provides a GraphQL API for WordPress sites. Prior to version 2.9.1, the `wp-graphql/wp-graphql` repository contains a GitHub Actions workflow (`release.yml`) vulnerable to OS command injection through direct use of `${{ github.event.pull_request.body }}` inside a `run:` shell block. When a…
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pull request from `develop` to `master` is merged, the PR body is injected verbatim into a shell command, allowing arbitrary command execution on the Actions runner. Version 2.9.1 contains a fix for the vulnerability.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.2.5V1.2.8V15.2.5
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect command sanitization during development.
Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.
Least privilege reduces the permissions available to any process that could be subverted by injected commands.
Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.
Secure engineering principles require proper neutralization of untrusted input before command construction.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.