CVE-2026-116391: Logo Slider PHP object injection vulnerability

high 8.8 published 2026-10-28 · updated 2026-10-29

Affected versions: 3.8.9 and older
Fixed in: 3.9.0
Latest version: 3.9.1
Severity: High · CVSS 8.8
Active installs: 30,000+
Type: PHP object injection

What an attacker needs

Access: A low-level account on the site, such as a subscriber or customer (per the CVSS score).

CVSS vector (score by Patchstack): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What to do now

Update Logo Slider to 3.9.0 or newer (the latest is 3.9.1): Dashboard → Updates, or Plugins → “update now”.
If you cannot update right away, deactivate it until you can.
Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
Not sure which version you run? Check your version against every known Logo Slider issue. With WP-CLI: wp plugin get gs-logo-slider --field=version.
If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.

The advisory

Deserialization of Untrusted Data vulnerability in GS Plugins GS Logo Slider gs-logo-slider allows Object Injection.This issue affects GS Logo Slider: from n/a through 3.8.9.

Description from the CVE record, published by Patchstack (the CVE Numbering Authority), via the NVD entry for CVE-2026-116391.

References

NVD CVE-2026-116391 nvd.nist.gov
Patchstack advisory patchstack.com

Ran an affected version? Check your site for signs of a hack

The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.

Where this data comes from

CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Versions and install counts: wordpress.org/plugins/gs-logo-slider (Plugins API), fetched 2026-11-04.
The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.