CVE-2026-75757
AshAdmin cookie reader matches names by substring, enabling actor/session shadowing from a sibling subdomain
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.
INFO
Published Date :
Aug. 31, 2026, 3:16 a.m.
Last Modified :
Aug. 31, 2026, 3:16 a.m.
Remotely Exploit :
Yes !
Source :
6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Affected Products
The following products are affected by CVE-2026-75757
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | ||||
| CVSS 4.0 | HIGH | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db |
Solution
- Update ash_admin to version 1.3.1 or later.
- Apply exact cookie name matching.
- Ensure cookies are properly validated.
- Review session management security.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-75757.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-75757 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-75757
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-75757 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-75757 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Aug. 31, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-565 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/75xxx/CVE-2026-75757.json">CVE-2026-75757</a> Added Reference https://cna.erlef.org/cves/CVE-2026-75757.html Added Reference https://github.com/ash-project/ash_admin/commit/e93a3408a85035e1f90275d02bc2470c96095e56 Added Reference https://github.com/ash-project/ash_admin/security/advisories/GHSA-3259-55fp-w94j Added Reference https://osv.dev/vulnerability/EEF-CVE-2026-75757