CVE-2026-66664 describes an unauthenticated Cross Site Scripting (XSS) vulnerability in the SEO Plugin by Squirrly SEO, affecting all versions up to and including 14.2.0. The vulnerability allows attackers to execute arbitrary scripts in the context of the affected application without requiring authentication. The CVSS 3.1 base score is 7.1, indicating high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the victim's browser, potentially leading to information disclosure, session hijacking, or other impacts on confidentiality, integrity, and availability as indicated by the CVSS vector. Because the vulnerability is unauthenticated, it can be exploited by remote attackers without credentials.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official patch or fix information is provided in the available data. Until a patch is available, users should monitor vendor communications for updates and consider applying any recommended temporary mitigations if provided.