CVE-2026-112862: Participants Database PHP object injection vulnerability

critical 9.8 plugin closed published 2026-10-23

Affected versions: 2.7.8.5 and older
Fixed in: unknown
Severity: Critical · CVSS 9.8
Active installs: closed
Type: PHP object injection

What an attacker needs

Access: None. No account or login is needed (per the CVSS score).

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

What to do now

Replace Participants Database. A closed plugin gets no updates through WordPress, so this hole stays open.
Deactivate and delete it once you have a replacement (Plugins → Deactivate → Delete). Deactivating alone leaves its files on the server.
Not sure which version you run? Check your version against every known Participants Database issue.
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 xnau webdesign Participants Database participants-database allows Object Injection.This issue affects Participants Database: from n/a through 2.7.8.5.

Description from the CVE record, published by Patchstack (the CVE Numbering Authority), via the NVD entry for CVE-2026-112862.

References

NVD CVE-2026-112862 nvd.nist.gov
Patchstack advisory patchstack.com

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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/participants-database (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.