Description
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.
Published: 2026-08-31
Score: 8.3 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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History

Mon, 31 Aug 2026 19:15:00 +0000

Type Values Removed Values Added
Description 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.
Title oasdiff actions resolve external $refs by default, enabling SSRF and disclosure of structured files on pull-request runs
Weaknesses CWE-1188
CWE-200
CWE-918
References
Metrics cvssV4_0

{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-31T18:57:41.097Z

Reserved: 2026-06-09T17:05:25.059Z

Link: CVE-2026-53507

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-31T19:16:49.867

Modified: 2026-08-31T19:16:49.867

Link: CVE-2026-53507

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-31T20:30:05Z

Weaknesses
  • CWE-1188

    Initialization of a Resource with an Insecure Default

  • CWE-200

    Exposure of Sensitive Information to an Unauthorized Actor

  • CWE-918

    Server-Side Request Forgery (SSRF)