# CVE-2026-75757

## Summary

- **CVE ID:** CVE-2026-75757
- **Severity:** HIGH
- **CVSS Score:** 8.3 (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-565
- **Published:** Aug 31, 2026
- **Last Modified:** Aug 31, 2026

## Description

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.

## Affected Products

- ash-project — ash_admin (0.9.1)
- ash-project — ash_admin (77a43cc4fa04cb59c38fc434568a35a38ecb995a)

## References

- [CNA](https://github.com/ash-project/ash_admin/security/advisories/GHSA-3259-55fp-w94j)
- [CNA](https://cna.erlef.org/cves/CVE-2026-75757.html)
- [CNA](https://osv.dev/vulnerability/EEF-CVE-2026-75757)
- [CNA](https://github.com/ash-project/ash_admin/commit/e93a3408a85035e1f90275d02bc2470c96095e56)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.30%
- **EPSS Percentile:** 22.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._