CVE-2025-4369

Companion Auto Update <= 3.9.2 - Authenticated (Administrator+) Stored Cross-Site Scripting via update_delay_days parameter

5.5 Medium

The Companion Auto Update plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘update_delay_days’ parameter in all versions up to, and including, 3.9.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: High
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.29%Up 0.3 points since Jul 15, 2025

What each source reports

CVE List Score used 5.5

Companion Auto Update <= 3.9.2 - Authenticated (Administrator+) Stored Cross-Site Scripting via update_delay_days parameter

Record: CVE-2025-4369
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

EUVDEUVD-2025-21421 5.5

Record: EUVD-2025-21421
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-99ch-c9wr-h7qc 5.5

The Companion Auto Update plugin for WordPress is vulnerable to Stored Cross-Site Scripting via...

Record: GHSA-99ch-c9wr-h7qc
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

NVD 5.5

Record: CVE-2025-4369
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

Affected products

papin companion auto update

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-4369 is a medium vulnerability (CVSS 5.5) in Papin Companion Auto Update, published July 15, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. No source names a fixed version.