CVE-2025-26903 Overview
CVE-2025-26903 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the RealMag777 InPost Gallery plugin for WordPress. The flaw impacts all versions up to and including 2.1.4.3. The issue is tracked under [CWE-352] (Cross-Site Request Forgery) and stems from missing or insufficient anti-CSRF token validation on state-changing plugin actions. Successful exploitation requires an authenticated user to interact with an attacker-crafted request, typically by visiting a malicious page while authenticated to the target WordPress site. The impact is limited to integrity, with no direct effect on confidentiality or availability.
Critical Impact
Attackers can trick authenticated WordPress users into performing unintended plugin actions, altering InPost Gallery state without their consent.
Affected Products
- RealMag777 InPost Gallery WordPress plugin (inpost-gallery)
- All versions from initial release through 2.1.4.3
- WordPress sites with the vulnerable plugin installed and activated
Discovery Timeline
- 2025-04-15 - CVE-2025-26903 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-26903
Vulnerability Analysis
The InPost Gallery plugin exposes plugin actions that modify server-side state without validating a WordPress nonce or equivalent anti-CSRF token. An attacker hosts a page that issues a forged request to the vulnerable endpoint. When an authenticated WordPress user visits that page, their browser automatically attaches session cookies, and the request executes with the user's privileges.
Because the vulnerability requires user interaction and yields only limited integrity impact, the practical scenarios are narrow. However, if an administrator is targeted, an attacker can modify plugin configuration or trigger plugin operations that alter gallery content or settings. The EPSS probability of 0.158% reflects a low observed likelihood of near-term exploitation.
Root Cause
The root cause is the absence of a valid WordPress nonce check (wp_verify_nonce or check_admin_referer) on one or more request handlers in InPost Gallery through version 2.1.4.3. Without nonce validation, the plugin cannot distinguish between legitimate user-initiated actions and forged cross-origin requests.
Attack Vector
Exploitation is network-based and requires user interaction. An attacker crafts an HTML page containing a form or image tag that targets a vulnerable InPost Gallery endpoint on the victim's WordPress site. The attacker then lures an authenticated user to visit the page through phishing, a comment link, or a compromised third-party site. The browser transmits authentication cookies with the forged request, and the plugin processes it as legitimate. See the Patchstack Vulnerability Advisory for advisory details.
Detection Methods for CVE-2025-26903
Indicators of Compromise
- Unexpected changes to InPost Gallery settings or gallery items with no corresponding administrator action in audit logs
- WordPress access logs showing POST requests to plugin endpoints with Referer headers pointing to external, untrusted domains
- Requests to InPost Gallery action handlers that lack a _wpnonce parameter
Detection Strategies
- Inventory WordPress sites for the inpost-gallery plugin at versions <= 2.1.4.3 using plugin management tooling or file-system scans for wp-content/plugins/inpost-gallery/
- Review web server logs for requests to InPost Gallery admin-ajax or admin-post endpoints originating from external referrers
- Correlate WordPress user session activity with plugin state changes to spot actions performed without matching UI navigation
Monitoring Recommendations
- Enable WordPress audit logging to capture plugin setting changes and administrative actions
- Alert on anomalous Referer values on authenticated POST requests to /wp-admin/ endpoints
- Track outbound clicks from webmail and CMS interfaces used by WordPress administrators to identify potential CSRF lures
How to Mitigate CVE-2025-26903
Immediate Actions Required
- Identify all WordPress installations running InPost Gallery <= 2.1.4.3 and prioritize sites with high-privilege user activity
- Update the plugin to a fixed release once published by the vendor, or deactivate and remove it if no patch is available
- Require administrators to log out of WordPress when not actively managing the site to shrink the CSRF exploitation window
Patch Information
At the time of publication, the vendor advisory tracked by Patchstack lists all versions through 2.1.4.3 as affected. Administrators should monitor the plugin's WordPress.org listing for a patched release and apply it promptly.
Workarounds
- Deactivate the InPost Gallery plugin until a fixed version is released
- Deploy a web application firewall rule that blocks POST requests to InPost Gallery endpoints missing a valid _wpnonce parameter
- Enforce SameSite=Lax or SameSite=Strict cookie attributes on WordPress authentication cookies to reduce cross-site request risk
- Restrict WordPress administrator access to dedicated browsers or sessions not used for general web browsing
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
