CVE-2026-96581

HIGH
MEDIUM Priority: 0.02 BB Relevance: 65/100
Published: 2026-10-26 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
AT: Present
VC: High
VI: High
VA: None

Description

Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash allows a user of one tenant to read, overwrite and take over another tenant's records via an upserting create action. Under attribute multitenancy, Ash.Actions.Create (lib/ash/actions/create/create.ex) and Ash.Actions.Create.Bulk (lib/ash/actions/create/bulk.ex) upserted on the primary key, or on an all_tenants? identity, without scoping the conflicting record to the request's tenant. A caller of a create action with upsert? true that accepts the primary key, supplying a record id from another tenant, updated that record's upsert fields and received all of its attributes in the result. With the default upsert fields the tenant attribute was written too, moving the record into the caller's tenant. Read and update policies do not run for upserts, and tenant-scoped create policies pass because the tenant is the caller's own. This issue affects ash: from 1.22.0 before 3.37.2.

Weakness Classification (1)

Bug Bounty Relevance

65 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

7.6 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

EPSS — Exploitation Probability

0.26%
Raw Score 0.002580
Percentile 17.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00258
2026-10-28
0.00258

Intelligence Sources

mitre ref →
nvd ref →