WordPress security changelog
MEDIUM CVE-2026-16953 Deferred

AI Engine guessable guest sessions permit deletion of another visitor's uploaded files

AI Engine exposes POST /wp-json/mwai-ui/v1/files/delete for guest file management. rest_delete() accepts file references in the files JSON field and authorizes them against the guest identity derived from the mwai_session_id cookie. Vulnerable releases generated that identity with predictable PHP uniqid() output and used it as the guest-file ownership key. An unauthenticated attacker who can obtain or enumerate a victim session identifier and knows a victim file reference can submit that identity and delete the victim's plugin-managed chatbot uploads. The CNA identifies 3.6.4 as fixed, but that release still accepted arbitrary legacy 13-hex session identifiers; official source removes that compatibility path in 3.6.6.

CVE / CNA score 4.8 CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD score Pending NVD has not published its own CVSS assessment.
Component
AI Engine
Plugin slug
ai-engine
Affected
< 3.6.4
Safe version
3.6.6
Published
Aug 08, 2026
Weakness
CWE-639 — Authorization Bypass Through User-Controlled Key

This CVE was published Aug 08, 2026 and is one of 35 known issues for this plugin.

Update, patch or deactivate.

Update to 3.6.6 or later. Clear old guest-session cookies where practical and restore deleted uploads from backups or re-upload them. Review request logs for unusual file-deletion calls.

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

The AI Engine WordPress plugin before 3.6.4 does not verify ownership of a guest's uploaded chatbot files before deletion, authorising the action solely by a client-supplied session cookie value, so an unauthenticated attacker who obtains a victim's session identifier and file reference can delete that victim's uploaded files.

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

Primary and upstream sources