CVE-2026-78264: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Site Building with Toolset Toolset Blocks

CVE-2026-78264 is an unauthenticated Cross-Site Scripting (CWE-79) vulnerability in Toolset Blocks versions <= 1.6.26. The flaw arises from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts that can affect confidentiality, integrity, and availability. The vulnerability is remotely exploitable without privileges and requires user interaction (UI:R). The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L, reflecting network attack vector, low attack complexity, no privileges required, user interaction required, scope changed, and low impact on confidentiality, integrity, and availability.

Successful exploitation of this vulnerability can lead to the execution of arbitrary scripts in the context of the affected web application, potentially resulting in data disclosure, modification, or disruption of service. The vulnerability affects confidentiality, integrity, and availability to a limited extent. Since it is unauthenticated, any remote attacker can attempt exploitation. However, user interaction is required to trigger the malicious script.

No official patch or remediation guidance is currently available from the vendor. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is released, users should consider applying web application firewall (WAF) rules to detect and block XSS attempts and limit exposure by restricting access where possible.