CVE Catalog

CVE-2026-53507

HighCVSS 8.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.29%

21th percentile - higher than 21% of all known CVEs

Summary

oasdiff-action is a GitHub Action that detects breaking changes in OpenAPI specs and post a review on every pull request. Before version 0.0.51, the oasdiff actions resolved external $refs in the OpenAPI spec by default (allow-external-refs: true). When an action runs on a pull request whose spec is attacker-controlled – most importantly fork pull requests on public repositories – a $ref in that spec is fetched/read on the runner with no interaction required, enabling SSRF and disclosure of structured files on the runner.

Risk Assessment

An attacker can exploit the GitHub Actions runner to scan internal networks, read files from the runner, and potentially access secrets or other sensitive data.

Recommendation

Update oasdiff-action to version 0.0.51 or later. Additionally, consider disabling external reference resolution or restricting action permissions in public repositories.

Related vulnerabilities

Original NVD description (English source)

oasdiff-action is a GitHub Action that detects breaking changes in OpenAPI specs and post a review on every pull request. Before version 0.0.51, the oasdiff actions resolved external $refs in the OpenAPI spec by default (allow-external-refs: true). When an action runs on a pull request whose spec is attacker-controlled — most importantly fork pull requests on public repositories — a $ref in that spec is fetched/read on the runner with no interaction required, enabling SSRF and disclosure of structured files on the runner. This issue has been patched in version 0.0.51.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS