Ash Framework EUVD-2026-68950

Exploitation requires all three of the following conditions simultaneously: (1) the targeted Ash resource must use the ETS (Ash.DataLayer.Ets) or Mnesia (Ash.DataLayer.Mnesia) data layer - resources backed by SQL data layers are entirely unaffected; (2) the resource's create action must accept actor-supplied values for one or more primary key attributes (e.g., an id field marked public?: true with create permissions) - resources where the primary key is exclusively auto-generated server-side without user input cannot be exploited because the attacker cannot choose a colliding key; and (3) the attacker must be able to invoke the create action at whatever privilege level the application's own authorization rules require. Keyless resources (those with no defined primary key) are also exempt because the fix explicitly allows synthetic-key creation for them using make_ref().

The CVSS 4.0 score of 5.9 (Medium) reflects high integrity impact tempered by the AT:P attack requirement - exploitation depends on the attacker controlling a user-supplied primary key value, which is a non-default configuration in many Ash applications. The AV:L designation in the vendor-provided CVSS 4.0 vector characterizes this as a local application-layer concern, though Ash is commonly deployed as a network-accessible web or API server, making AV:N a plausible alternative framing for affected deployments; this discrepancy should be verified against the specific deployment topology. No CISA KEV listing and no public exploit code mean current real-world risk is limited to informed, targeted attackers who understand the affected application's data model. Applications using SQL data layers such as AshPostgres are entirely unaffected regardless of version. EPSS score was not provided in the input data.

An attacker with access to a create endpoint for an ETS-backed Ash resource - for example, a GraphQL mutation or REST API call that accepts a user-supplied string ID - submits a create request using the known or predicted primary key of a victim record; because the ETS data layer performed an unconditional keyed write (ETS.Set.put), the victim's record is silently replaced with the attacker's payload, bypassing all update action authorization policies. No public exploit code has been identified; the scenario is inferred directly from the vulnerability description and the reviewed commit diff.