CVE-2026-53507oasdiff actions resolve external $refs by default, enabling SSRF and disclosure of structured files on pull-request runs
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 8.3 HIGH (v4.0, CNA)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
- Weakness (CWE)
- CWE-200, CWE-918, CWE-1188
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Deferred
- Record last updated
- Sep 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
oasdiff oasdiff-action oasdiff:action (from the name) | before 0.0.51 | CNA record |
References
- https://github.com/oasdiff/oasdiff-action/security/advisories/GHSA-fhj3-7267-7vv5x-refsource-confirm
- https://github.com/oasdiff/oasdiff-action/pull/128x-refsource-misc
- https://github.com/oasdiff/oasdiff-action/pull/129x-refsource-misc
- https://github.com/oasdiff/oasdiff-action/pull/130x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.