WPGSI: Spreadsheet Integration <= 3.8.3 - Missing Authorization to Unauthenticated Arbitrary Post Creation and Deletion via Forged Base64 Token

Missing Authorization
CVE CVE-2026-1916
CVSS High (7.5)
Publicly Published February 24, 2026
Last Updated February 25, 2026
Researcher Osvaldo Noe Gonzalez Del Rio (Os)
Description

The WPGSI: Spreadsheet Integration plugin for WordPress is vulnerable to unauthorized modification and loss of data due to missing capability checks and an insecure authentication mechanism on the `wpgsi_callBackFuncAccept` and `wpgsi_callBackFuncUpdate` REST API functions in all versions up to, and including, 3.8.3. Both REST endpoints use `permission_callback => '__return_true'`, allowing unauthenticated access. The plugin's custom token-based validation relies on a Base64-encoded JSON object containing the user ID and email address, but is not cryptographically signed. This makes it possible for unauthenticated attackers to forge tokens using publicly enumerable information (admin user ID and email) to create, modify, and delete arbitrary WordPress posts and pages, granted they know the administrator's email address and an active integration ID with remote updates enabled.

References

1 affected software package

Software Type Plugin
Software Slug wpgsi (view on wordpress.org)
Patched? Yes
Affected Version
  • <= 3.8.3
Patched Version
  • 3.8.4
This record contains material that is subject to copyright

Copyright 2012-2026 Defiant Inc.
License: Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy. License Detail.