HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, an attack chain utilizing Stored XSS alongside dynamic token exposure in the `/system/api/connectionSettings` endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the `jwt`, `user_token`, `site_token`, and `appstore_token`) into a global JavaScript variable (`window.appSettings`). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook. Version 26.0.0 patches the issue.
https://github.com/haxtheweb/issues/security/advisories/GHSA-x3x5-7h4h-gwxg
Published: 2026-06-05
Updated: 2026-06-08
Base Score: 3.5
Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N
Severity: Low
Base Score: 5.4
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00071