CVE-2026-27938
CVE-2026-27938 is a high-severity vulnerability with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.
Key facts
- Severity: High (CVSS 3.x base score 7.7)
- EPSS exploit prediction: 1% (52nd percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-8803
- Weakness: CWE-78
- Published:
- Last modified:
Description
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 `${{ github.event.pull_request.body }}` inside a `run:` shell block. When a pull request from `develop` to `master` is merged, the PR body is injected verbatim into a shell command, allowing arbitrary command execution on the Actions runner. Version 2.9.1 contains a fix for the vulnerability.
Frequently asked questions
- What is CVE-2026-27938?
- WPGraphQL provides a GraphQL API for WordPress sites. Prior to version 2.9.1, the `wp-graphql/wp-graphql` repository contains a GitHub Actions workflow (`release.yml`) vulnerable to OS command injection through direct use of `${{ github.event.pull_request.body }}` inside a `run:` shell block. When a 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.
- How severe is CVE-2026-27938?
- CVE-2026-27938 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
- Is CVE-2026-27938 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-27938?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-27938 have an EU (EUVD) identifier?
- Yes. CVE-2026-27938 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8803.
- When was CVE-2026-27938 published?
- CVE-2026-27938 was published on 2026-02-26 and last updated on 2026-06-17.
References
- https://github.com/wp-graphql/wp-graphql/commit/de0c2d590593f1099546ad517106e454a498bc58
- https://github.com/wp-graphql/wp-graphql/security/advisories/GHSA-4q9f-mjxf-rx7x
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