WordPress security changelog
CRITICAL CVE-2026-78265 Deferred

The Events Calendar permits unauthenticated PHP object injection

The Events Calendar through 6.17.2 permits an unauthenticated attacker to supply serialized data to an unsafe PHP deserialization operation. A usable object chain can compromise site confidentiality, integrity, and availability.

CVE / CNA score 9.8 CVSS 3.1 · audit@patchstack.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
The Events Calendar
Plugin slug
the-events-calendar
Affected
n/a through 6.17.2
Safe version
6.17.3
Published
Aug 24, 2026
Weakness
CWE-502 — Deserialization of Untrusted Data

This CVE was published Aug 24, 2026 and is one of 28 known issues for this plugin.

Update, patch or deactivate.

Update to 6.17.3 or later and inspect files, accounts, scheduled tasks, and logs for evidence of compromise.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Technical description

Unauthenticated PHP Object Injection in The Events Calendar <= 6.17.2 versions.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary and upstream sources