EEF-CVE-2026-75757

## Summary

Reliance on Cookies without Validation and Integrity Checking vulnerability in ash-project ash\_admin lets an attacker who controls a sibling subdomain rebind an admin's session to a different actor, tenant, or authorization mode.

AshAdmin's client JavaScript read its state cookies (tenant, actor\_resource, actor\_primary\_key, actor\_action, actor\_domain, actor\_authorizing, actor\_paused) by matching the cookie name with an unanchored regular expression (new RegExp(name + "=(\[^;\]+)")) against the whole document.cookie. Any cookie whose name merely ends with the requested name therefore matches, and whichever is serialized first wins. Because cookies are shared across a registrable domain, a compromised sibling subdomain can set a shadowing cookie (for example xactor\_authorizing) with Domain=.example.com that flows unvalidated into the admin's LiveSocket connect params. The fix matches cookie names by exact equality.

This issue affects ash\_admin: from 0.9.1 before 1.3.1.