CVE-2026-53507

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. This issue has been patched in version 0.0.51.

Affected Software

VendorProductVersion RangeStatus
oasdiffoasdiff-action< 0.0.51affected

Weaknesses

  • CWE-200: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-918: CWE-918: Server-Side Request Forgery (SSRF)
  • CWE-1188: CWE-1188: Insecure Default Initialization of Resource

References