medium

CVE-2026-53508

Go · github.com/oasdiff/oasdiff

Summary

oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read)

Severity
medium
EPSS
0.3% (p21)
CWE
CWE-73, CWE-693, CWE-918
Also known as
GHSA-2jcc-mxv7-p3f9
Published
2026-07-07
Updated
2026-07-07

Advisory details

Summary

From v1.13.2 through v1.18.0, oasdiff did not enforce --allow-external-refs=false (library: openapi3.Loader.IsExternalRefsAllowed = false) when loading a spec from a git revision (the rev:path form, e.g. main:openapi.yaml). External $refs were resolved on that load path even when external refs were explicitly disabled, so the mitigation silently did not apply there.

Impact

A caller who set --allow-external-refs=false specifically to safely process untrusted specs remained exposed — on the git-revision load path only — to:

Affected callers:

The file and URL load paths correctly enforced the setting; only the git-revision path was affected. Callers that left external refs at the default (true) are not in scope for this advisory.

Patches

v1.18.1 enforces the external-refs policy on the git-revision path (so --allow-external-refs=false now blocks external $refs there) and returns a dedicated exit code (123) when an external $ref is refused.

Workarounds

Notes

References

Related advisories

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Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.