CVE-2026-96581highCWE-639

CVE-2026-96581: high-severity vulnerability in ash-project ash

An upsert on the primary key in Ash ignores attribute multitenancy, so one tenant can read, overwrite and take over another tenant's records

Published

Follow this CVE+ Monitor ash+ Monitor ash

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.6epss 0.3%
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.
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
Affected products
ash-project · ash
Related CVEs — ash-project ash

In the same product, most dangerous first.

CVE-2025-48044HIGHAuthorization bypass when bypass policy condition evaluates to trueEPSS 0.7%CVE-2026-67579HIGHFilter expression injection via forged keyset pagination cursor in AshEPSS 0.6%CVE-2026-34593HIGHAsh Framework: Ash.Type.Module.cast_input/2 atom exhaustion via unchecked Module.concat allows BEAM VM crashEPSS 0.4%CVE-2026-86338MEDIUMAsh field policies do not filter-nil forbidden calculations and aggregates, enabling an information-disclosure oracleEPSS 0.4%CVE-2025-48043HIGHBypass and runtime policies that can never pass may be incorrectly applied in filter authorizationEPSS 0.4%CVE-2026-69659MEDIUMMemory exhaustion via unbounded deserialization of keyset pagination cursors in Ash.Page.KeysetEPSS 0.4%