oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read) (CVE-2026-53508) | HOL Guard CVE

Medium · CVSS 6.0CVE-2026-53508GHSA-2JCC-MXV7-P3F9

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

Answer in brief

CVE-2026-53508 records a Medium severity (CVSS 6.0) vulnerability in oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read). The current sources do not mark it as known exploited. The current feed maps oasdiff/oasdiff (generic), github.com/oasdiff/oasdiff (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 31, 2026Updated Sep 9, 2026Source checked Sep 17, 2026First seen by HOL Jul 8, 2026Material review Sep 9, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.0
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps oasdiff/oasdiff (generic), github.com/oasdiff/oasdiff (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
oasdiff/oasdiffgeneric	>= 1.13.2, < 1.18.1	Not reported
github.com/oasdiff/oasdiffgo	>=1.13.2,<=1.18.0	1.18.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for oasdiff/oasdiff, github.com/oasdiff/oasdiff.
Review the reported fix. Update github.com/oasdiff/oasdiff to 1.18.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 8, 2026

Sources and claim methodology

Upstream source description

oasdiff is a command-line and Go package that compares and detects breaking changes in OpenAPI specs. From version 1.13.2 through version 1.18.0, 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. This issue has been patched in version 1.18.1.

Quoted source text, attributed separately from HOL analysis.