XSS in Smub Photo Gallery, Sliders, Proofing And Themes – Nextgen Gallery

CVE-2026-116563

The Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'comment' parameter in all versions up to, and including, 4.5.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the site to have Shutter or Shutter Reloaded selected as the active lightbox, and the injected comment must be approved through WordPress's standard moderation workflow before the payload is rendered to other visitors.

Vulnerability class: XSS (Cross-Site Scripting)

Published .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-116563?
CVE-2026-116563 is a medium-severity vulnerability in Smub Photo Gallery, Sliders, Proofing And Themes – Nextgen Gallery, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-10-31.
How severe is CVE-2026-116563?
Medium severity. CVSS v3 base score is 5.4 out of 10.