CVE-2026-78280 Overview
CVE-2026-78280 is an unauthenticated Cross-Site Request Forgery (CSRF) vulnerability affecting the Hash Form WordPress plugin in versions up to and including 1.4.0. The flaw is categorized under [CWE-352] and stems from missing or improper anti-CSRF token validation on state-changing requests. An attacker can craft a malicious page or link that, when visited by an authenticated user, triggers unintended actions in the plugin context. Exploitation requires user interaction but does not require attacker authentication.
Critical Impact
A tricked administrator visiting an attacker-controlled page can cause unauthorized state changes within the Hash Form plugin, resulting in limited integrity impact on the WordPress site.
Affected Products
- Hash Form WordPress plugin versions <= 1.4.0
- WordPress installations with the Hash Form plugin activated
- Any site administrator session interacting with attacker-controlled content while the plugin is installed
Discovery Timeline
- 2026-08-24 - CVE-2026-78280 published to NVD
- 2026-08-24 - Last updated in NVD database
Technical Details for CVE-2026-78280
Vulnerability Analysis
The Hash Form plugin fails to enforce anti-CSRF protections on one or more request handlers. WordPress provides nonce mechanisms via wp_nonce_field() and check_admin_referer() for exactly this purpose. When these controls are missing, the browser will attach a victim's authenticated session cookies to any request initiated by an attacker-controlled origin. The attacker leverages this cookie behavior to submit forged state-changing requests on behalf of the victim.
The network attack vector and low complexity mean an attacker only needs to lure a logged-in user to a malicious URL. User interaction is required, which is why the impact is limited to integrity without confidentiality or availability effects.
Root Cause
The root cause is missing CSRF token validation on request handlers exposed by the Hash Form plugin. Requests are processed based on session cookies alone, without verifying that the request originated from a trusted, same-origin form. This class of flaw maps directly to [CWE-352] Cross-Site Request Forgery.
Attack Vector
An attacker hosts a page containing an auto-submitting HTML form or JavaScript-driven fetch() call targeting the vulnerable endpoint. When a WordPress user with the appropriate role visits the page, the browser transmits their session cookies with the forged request. The plugin processes the request as legitimate. See the Patchstack Vulnerability Report for technical details.
Detection Methods for CVE-2026-78280
Indicators of Compromise
- Unexpected modifications to Hash Form plugin configuration or form definitions in the WordPress database
- HTTP POST or GET requests to plugin endpoints with Referer headers pointing to external, untrusted origins
- Administrator actions logged from unusual client IPs or during off-hours user activity
Detection Strategies
- Inspect web server access logs for requests to /wp-admin/admin.php?page=hash-form* and related plugin endpoints originating from cross-origin referrers
- Correlate authenticated admin sessions with concurrent third-party page visits in browser telemetry
- Alert on plugin configuration changes that lack a corresponding admin console interaction
Monitoring Recommendations
- Enable WordPress audit logging to capture plugin setting changes and form submissions
- Monitor for anomalous outbound referrers preceding administrative actions
- Track version inventory of the Hash Form plugin across managed WordPress instances
How to Mitigate CVE-2026-78280
Immediate Actions Required
- Update the Hash Form plugin to a version later than 1.4.0 once a patched release is available from the vendor
- If no patch is available, deactivate and remove the plugin from production WordPress sites
- Instruct administrators to log out of WordPress before browsing untrusted sites
Patch Information
Refer to the Patchstack Vulnerability Report for the latest vendor patch status. Apply the fixed version as soon as it is published to the WordPress plugin repository.
Workarounds
- Deploy a Web Application Firewall (WAF) rule to block cross-origin requests to Hash Form plugin endpoints
- Enforce SameSite=Lax or SameSite=Strict cookie attributes on WordPress authentication cookies where compatible
- Restrict administrative access by IP allowlist at the reverse proxy or WAF tier
- Require administrators to use dedicated browsers or sessions isolated from general web browsing
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
