CVE-2025-13856 MEDIUM

CVE-2025-13856: Extra Post Images <= 1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

Vendor Michaelcole1991
Product Extra Post Images
Weakness CWE-79 · XSS
Published December 6, 2025
Last update April 8, 2026

CVSS base score

6.4/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

What the vulnerability does

01Description

The Extra Post Images plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' parameter of the extra-images shortcode in all versions up to, and including, 1.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Explanation of Vulnerability in Simple Terms

02Summary

Extra Post Images versions 1.0 and earlier contain a cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious scripts affecting other users on the site. The vulnerability has a changed scope, meaning the impact extends beyond the vulnerable component itself. Low-privileged users can exploit this without user interaction from victims.

What an attacker can do

03Attacker Capabilities

Inject malicious scripts that execute in other users' browsers and affect site functionality.

Potential impact on your site

04Site Impact

Authenticated users can inject scripts affecting other users' sessions and site behavior; requires account access to exploit.

Conditions required to exploit

05Prerequisites

Attacker must have a low-privilege account (e.g., contributor or subscriber role) on the site.

Key dates

06Disclosure timeline

December 6, 2025 CVE published
April 8, 2026 Record updated