WPGSI: Spreadsheet Integration: Missing Authorization
CVE-2026-1916 is a high-severity missing authorization vulnerability in WPGSI: Spreadsheet Integration from Javmah, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected WPGSI: Spreadsheet Integration versions: 3.8.3 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.41% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of WPGSI: Spreadsheet Integration you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Javmah | WPGSI: Spreadsheet Integration | 3.8.3 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (wordfence.com).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
How developers prevent this class of flaw
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- plugins.trac.wordpress.org/browser/wpgsi/tags/3.8.3/admin/class-wpgsi-update.php#L116
- plugins.trac.wordpress.org/browser/wpgsi/tags/3.8.3/admin/class-wpgsi-update.php#L636
- plugins.trac.wordpress.org/browser/wpgsi/tags/3.8.3/admin/class-wpgsi-update.php#L94
- plugins.trac.wordpress.org/browser/wpgsi/trunk/admin/class-wpgsi-update.php#L116
- plugins.trac.wordpress.org/browser/wpgsi/trunk/admin/class-wpgsi-update.php#L636
- plugins.trac.wordpress.org/browser/wpgsi/trunk/admin/class-wpgsi-update.php#L94
- plugins.trac.wordpress.org/changeset/3461326/wpgsi/trunk/admin/class-wpgsi-update.php
- wordfence.com/threat-intel/vulnerabilities/id/7598b38b-26b1-4640-9bd7-60613a5f704d?source=cve
Recent Missing Authorization vulnerabilities
- 8.1 High severity
- 7.1 High severity
- 8.1 High severity
- 8.8 High severity
- 8.8 High severity
- 8.2 High severity
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