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Fencer Intel
critical 9.8

CVE-2026-89324 json

Basel Post Types <= 1.18 - Unauthenticated Authentication Bypass via Forged Opauth Callback Signature with Hardcoded Fallback Salt

published yesterday modified yesterday also EUVD-2026-122966

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

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.

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Exploit prediction

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • XTemos Basel Post Types

Classification

Weakness
Technology feeds

References

Sources

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