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CVE-2026-16267 - Before 4 Plugin

CVE-2026-16267

The Newsletters WordPress plugin before 4.16 does not restrict the classes allowed when unserialising a value taken from a public form submission, allowing unauthenticated attackers to inject arbitrary PHP objects.

CVE-2026-16267

UNKNOWN CVSS 0.0 Published 2026-08-08 Updated 2026-08-08
AI Risk Low (6/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P5 Monitor
Severity Band UNKNOWN
CVSS Vector Unspecified
Affected Components 2
Reference Links 1
AI Risk Engine Low (6/100)
Exploitability Low
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-08-08 CVE published and first recorded in the threat feed.
  2. 2026-08-08 Record updated with latest vulnerability metadata.
  3. 2026-08-08 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 7 hours ago

AI enriched 7 hours ago (2026-08-08 18:21 UTC)

Technical Summary

The Newsletters WordPress plugin before 4.16 does not restrict the classes allowed when unserialising a value taken from a public form submission, allowing unauthenticated attackers to inject arbitrary PHP objects.

Potential Impact

Severity is UNKNOWN (CVSS 0.0). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Low 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 6/100 (Low, Low) with priority P5 Monitor. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Before 4 PLUGIN · before-4 Affected: < 4.16 Fixed in: 4.16
Newsletters PLUGIN · newsletters Affected: < 4.16 Fixed in: 4.16
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