Auth bypass in Smub Photo Gallery, Sliders, Proofing And Themes – Nextgen Gallery

CVE-2026-6566

The Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to and including 4.2.0. This is due to insufficient object-level authorization in the image deletion REST flow where the permission callback for DELETE /imagely/v1/images/{id} only checks 'NextGEN Manage gallery' permissions and does not enforce gallery ownership or 'NextGEN Manage others gallery' permissions. This makes it possible for authenticated attackers, with Subscriber-level privileges and 'NextGEN Manage gallery' capability, to delete gallery images belonging to other users as well as their associated image files from disk when deleteImg is enabled (default).

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (16.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-6566: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-6566?
CVE-2026-6566 is a medium-severity vulnerability in Smub Photo Gallery, Sliders, Proofing And Themes – Nextgen Gallery, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2026-05-20.
How severe is CVE-2026-6566?
Medium severity. CVSS v3 base score is 4.3 out of 10.