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CVE-2026-16940 - Before 1 Plugin

CVE-2026-16940

The Custom Fields WordPress plugin before 1.5.1 does not validate a user-supplied file path before deletion, allowing unauthenticated users to delete arbitrary files on the server (such as wp-config.php), which can lead to a full site takeover.

CVE-2026-16940

CRITICAL CVSS 10.0 Published 2026-08-05 Updated 2026-08-06
AI Risk Critical (98/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P1 Immediate
Severity Band CRITICAL
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H
Affected Components 2
Reference Links 1
AI Risk Engine Critical (98/100)
Exploitability High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-08-05 CVE published and first recorded in the threat feed.
  2. 2026-08-06 Record updated with latest vulnerability metadata.
  3. 2026-08-07 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated just now

AI enriched just now (2026-08-07 20:24 UTC)

Technical Summary

The Custom Fields WordPress plugin before 1.5.1 does not validate a user-supplied file path before deletion, allowing unauthenticated users to delete arbitrary files on the server (such as wp-config.php), which can lead to a full site takeover.

Potential Impact

Severity is CRITICAL (CVSS 10.0). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on low-bar exploit prerequisites.

Primary risk drivers: low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 98/100 (Critical, High) with priority P1 Immediate. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Before 1 PLUGIN · before-1 Affected: < 1.5.1 Fixed in: 1.5.1
Custom Fields PLUGIN · custom-fields Affected: < 1.5.1 Fixed in: 1.5.1
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