CVE-2026-89324: CVE-2026-89324: The Basel Post Types plugin for WordPress is vulnerable to Authentication Bypass in all ve…

CVE-2026-89324 at a glance

CVE-2026-89324 is a critical-severity Auth Bypass vulnerability in Basel Post Types WordPress plugin, with a CVSS 3.1 base score of 9.8. NVD published it on 2026-11-11 and classifies the weakness as CWE-287. NVD does not list a fixed version, so the vendor advisory is the reference for the fix. CVERadar maps 2 MITRE ATT&CK techniques across Initial Access, Stealth, Persistence and Privilege Escalation, inferred from the CWE and the description. Its CVERadar threat level is 49/100.

What it is

The Basel Post Types plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 1.18. The vulnerability exists because a missing-quotes coding error in the defined() call for SECURE_AUTH_SALT inside BASEL_Auth::get_config() causes PHP to evaluate the constant's value rather than its name, making the check always fail and permanently falling back to the static hardcoded salt 2NlBUibcszrVtNmDnxqDbwCOpLWq91eatIz6O1O that is publicly visible in the theme source code; because this salt is static and known, an attacker can compute a valid Opauth signature entirely offline and submit a forged ?opauth callback to the unauthenticated init hook endpoint processed by register_or_login. This makes it possible for unauthenticated attackers to authenticate as any existing WordPress user, including administrators, by forging a callback tied to a known target account email address — bypassing all password verification, multi-factor authentication, and ownership checks, and receiving a fully authenticated session cookie via wc_set_customer_auth_cookie(). Exploitation requires WooCommerce to be active and at least one Basel social-login provider (Facebook, Google, or VKontakte) to be configured with a valid app_id and app_secret in the theme settings.

Exploitation evidence

Exploited in the wild

No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).

Public exploit code

GitHub proof-of-concept repositories below quality bar

1 public repositories from 1 accounts, first seen 2026-11-11.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: nomi-sec/PoC-in-GitHub.

Patches, mitigations and detection

Fixed versions

NVD does not list a fixed version for this CVE. Use the vendor advisory below.

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

No vendor-tagged reference yet; see the full reference list.

MITRE ATT&CK mitigations for this chain

• M1048 Application Isolation and Sandboxing (for T1190) : Application isolation will limit what other processes and system features the exploited target can access.
• M1037 Filter Network Traffic (for T1190) : Restrict outbound network traffic from public-facing servers to prevent unauthorized connections from initiating communications with attacker-controlled infrastructure. While this may not prevent the initial exploitation, it limits the attacker's ability to verify and control the compromised server post-exploit, reduci
• M1030 Network Segmentation (for T1190) : Segment externally facing servers and services from the rest of the network with a DMZ or on separate hosting infrastructure.
• M1016 Vulnerability Scanning (for T1190) : Regularly scan externally facing systems for vulnerabilities and establish procedures to rapidly patch systems when critical vulnerabilities are discovered through scanning and through public disclosure.
• M1026 Privileged Account Management (for T1190, T1078) : Use least privilege for service accounts will limit what permissions the exploited process gets on the rest of the system.
• M1050 Exploit Protection (for T1190) : Web Application Firewalls may be used to limit exposure of applications to prevent exploit traffic from reaching the application.
• M1035 Limit Access to Resource Over Network (for T1190) : Ensure that all publicly exposed services are actually intended to be so, and restrict access to any that should only be available internally.
• M1051 Update Software (for T1190) : Update software regularly by employing patch management for externally exposed applications.
• M1027 Password Policies (for T1078) : Applications and appliances that utilize default username and password should be changed immediately after the installation, and before deployment to a production environment. When possible, applications that use SSH keys should be updated periodically and properly secured. Policies should minimize (if not eliminate)
• M1018 User Account Management (for T1078) : Regularly audit user accounts for activity and deactivate or remove any that are no longer needed.

Detection Generic guidance

• Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
• Persistence: Look for new files in web roots, new scheduled tasks/services, and new accounts created after the exposure window.
• Privilege Escalation: Alert on processes gaining SYSTEM/root unexpectedly, and on exploitation crashes of privileged services.

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

Before patching, it helps to know every exposed instance; external attack surface monitoring from LayerLogix does that inventory.