Description

The wpForo Forum plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.1.5. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to take over another guest author's forum post and modify its title, body, author name, and stored owner email address. This requires that guest posting and editing are enabled on the forum, and that the attacker knows the target guest author's email address.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-09-22T08:16:41.090Z",
  "pubdate": "2026-09-22T08:16:41.090Z",
  "executiveSummary": "The wpForo Forum plugin for WordPress contains an authorization bypass vulnerability affecting all versions up to and including 3.1.5.\nThe vulnerability allows authenticated users with at least subscriber-level access to perform unauthorized modifications to forum posts created by guest authors.\nBy manipulating request parameters, an attacker can overwrite post metadata, including the title, body, author display name, and the associated email address, effectively facilitating account or post takeover.\nThe exploitation of this flaw requires that the forum configuration has guest posting and editing features enabled.\nAn attacker must possess knowledge of the target guest author's email address to execute the attack successfully.\nThis security flaw represents a significant risk to data integrity and forum content governance, as it allows malicious actors to impersonate guest contributors and modify user-generated content without proper administrative authorization.",
  "technicalDetails": "The root cause of this vulnerability lies in an improper implementation of authorization checks within the wpForo Forum plugin's post-processing logic.\nThe plugin fails to validate whether the current authenticated session possesses the necessary permissions to modify a specific forum post when guest editing is facilitated.\nWhen a user submits an update request, the application backend neglects to cryptographically or session-bound verify the ownership of the post against the authenticated user ID, instead relying on client-provided identifiers.\nThe attack flow begins with an authenticated attacker, holding at least subscriber-level privileges, identifying a target forum post created by a guest author.\nThe attacker observes the request structure used during the post-editing process. By capturing the HTTP request, the attacker can inject specific parameters that correspond to the desired target post ID.\nTo successfully hijack the post, the attacker provides the known email address associated with the target guest author within the request body. Because the plugin lacks sufficient server-side validation to ensure the attacker is indeed the owner of that email address, the application accepts the modified data as legitimate.\nThe system subsequently updates the post in the database, overwriting the original post's title, body, display name, and stored owner email address with the attacker's supplied values.\nThe vulnerability is present in versions up to and including 3.1.5. It specifically affects the logic handling guest content management where standard user roles bypass permission checks that should be applied to posts not owned by the current session user.\nThe impact of a successful exploitation is complete content control over guest-authored posts. The attacker can effectively censor or alter the narrative of existing posts and gain control over the identity associated with the content by modifying the stored email address.\nThis flaw is accessible via standard network vectors where the WordPress application is hosted, requiring only that the attacker has authenticated access to the platform and that the specific plugin settings for guest interaction are toggled on."
}