CVE-2026-53507

HIGHPre-NVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 79% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
8.3
EG Score
8.3(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity83% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
21%
KEV
Not listed

Published

August 31, 2026

Last Modified

September 9, 2026

Advisory Details (4)

Auto-updated Aug 31, 2026
Patch available. Sources: github, github_pr.
github_pr Patch Available

actions: surface genuine oasdiff errors as PR annotations

Patch available: oasdiff/oasdiff-action v0.0.51 (PR #130 merged 2026-05-31)

https://github.com/oasdiff/oasdiff-action/pull/130
github_pr Patch Available

bump: oasdiff v1.18.1

Patch available: oasdiff/oasdiff-action v0.0.51 (PR #129 merged 2026-05-30)

https://github.com/oasdiff/oasdiff-action/pull/129
github_pr Patch Available

harden: default allow-external-refs to false in the actions

Patch available: oasdiff/oasdiff-action v0.0.51 (PR #128 merged 2026-05-30)

https://github.com/oasdiff/oasdiff-action/pull/128
github Patch Available

oasdiff actions resolve external $refs by default, enabling SSRF and disclosure of structured files on pull-request runs · Advisory · oasdiff/oasdiff-action · GitHub

https://github.com/oasdiff/oasdiff-action/security/advisories/GHSA-fhj3-7267-7vv5

Weakness Classification(3)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 35× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 19:22 UTCEG score recompute
  2. 2026-09-19 05:54 UTCEG score recompute
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 03:30 UTCEG score recompute
  5. 2026-09-17 01:04 UTCEG score recompute
  6. 2026-09-16 14:08 UTCEPSS rescore
  7. 2026-09-16 11:53 UTCEG score recompute
  8. 2026-09-16 05:15 UTCEPSS rescore
  9. 2026-09-15 09:29 UTCEG score recompute
  10. 2026-09-13 17:54 UTCEG score recompute
  11. 2026-09-13 16:47 UTCEPSS rescore
  12. 2026-09-12 15:31 UTCEG score recompute
  13. 2026-09-12 02:19 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-11 13:07 UTCEG score recompute
  16. 2026-09-10 10:23 UTCEG score recompute
  17. 2026-09-10 09:35 UTCEPSS rescore
  18. 2026-09-08 23:29 UTCEG score recompute
  19. 2026-09-08 22:01 UTCEPSS rescore
  20. 2026-09-07 18:56 UTCEG score recompute
  21. 2026-09-07 16:01 UTCEPSS rescore
  22. 2026-09-06 16:33 UTCEG score recompute
  23. 2026-09-06 13:47 UTCEPSS rescore
  24. 2026-09-06 03:21 UTCEG score recompute
  25. 2026-09-05 00:56 UTCEG score recompute
Show 10 more
  1. 2026-09-04 11:40 UTCEG score recompute
  2. 2026-09-04 05:06 UTCEPSS rescore
  3. 2026-09-02 20:03 UTCEG score recompute
  4. 2026-09-02 14:12 UTCEPSS rescore
  5. 2026-09-01 15:43 UTCEG score recompute
  6. 2026-09-01 15:02 UTCEG score recompute
  7. 2026-09-01 13:54 UTCEPSS rescore
  8. 2026-08-31 19:28 UTCEG score recompute
  9. 2026-08-31 19:06 UTCEG score recompute
  10. 2026-08-31 19:04 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-53507?
CVE-2026-53507 is a high vulnerability published on August 31, 2026. 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…
When was CVE-2026-53507 disclosed?
CVE-2026-53507 was first published in the National Vulnerability Database on August 31, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53507 actively exploited?
CVE-2026-53507 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 78.7% of all scored CVEs.
What is the CVSS score of CVE-2026-53507?
CVE-2026-53507 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-53507?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53507, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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