CVE-2026-87966

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-09-18. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

The Easy Appointments WordPress plugin before 4.0.2.2 does not perform an ownership or authorization check on its unauthenticated appointment-reservation endpoint before updating an existing appointment identified by a request-supplied id, allowing unauthenticated attackers to overwrite, and through a follow-on cleanup delete, arbitrary appointments.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
13%
KEV
Not listed

Published

September 18, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated Sep 18, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Easy Appointments 4.0 – 4.0.2.1 – Unauthenticated Arbitrary Appointment Modification and Deletion via IDOR | CVE 2026-87966 | Plugin Vulnerabilities

https://wpscan.com/vulnerability/e2e625f4-c146-4622-b439-3179c4484613/

Vendor Advisories for CVE-2026-87966(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 15× 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. 2026-09-20 23:12 UTCEG score recompute
  2. 2026-09-20 23:12 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-19 21:13 UTCEG score recompute
  5. 2026-09-19 21:13 UTCGHSA enrichment
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-18 19:14 UTCEG score recompute
  8. 2026-09-18 19:14 UTCGHSA enrichment
  9. 2026-09-18 12:21 UTCGHSA enrichment
  10. 2026-09-18 11:19 UTCEG score recompute▲ 5.30
  11. 2026-09-18 11:19 UTCGHSA enrichment
  12. 2026-09-18 11:19 UTCMITRE cvelistV5CVSS v3 → 5.3 · severity → MEDIUM
  13. 2026-09-18 06:21 UTCNVD update
  14. 2026-09-18 06:04 UTCEG score recompute
  15. 2026-09-18 06:04 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-87966?
CVE-2026-87966 is a medium vulnerability published on September 18, 2026. The Easy Appointments WordPress plugin before 4.0.2.2 does not perform an ownership or authorization check on its unauthenticated appointment-reservation endpoint before updating an existing appointment identified by a request-supplied id, allowing unauthenticated attackers to overwrite, and…
When was CVE-2026-87966 disclosed?
CVE-2026-87966 was first published in the National Vulnerability Database on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87966 actively exploited?
CVE-2026-87966 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 87.1% of all scored CVEs.
What is the CVSS score of CVE-2026-87966?
CVE-2026-87966 has a CVSS v3.1 base score of 5.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-87966?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87966, 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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