CVE-2026-80223: Cross-tenant subscription disclosure in AshGraphql authorizes notifications in memory without a tenant-scoped read

Severity: high (CVSS 7.1 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-30 · updated 2026-09-03
Weakness: CWE-863

Description

Incorrect Authorization vulnerability in ash-project ash_graphql allows an authenticated subscriber in one tenant to receive another tenant's records over GraphQL subscriptions. The subscription resolver in AshGraphql.Graphql.Resolver authorizes each notification payload in memory: its fast path calls Ash.can/3 with run_queries?: false, which evaluates the read policy filter against the in-memory record via Ash.Expr.eval/2 and never issues a query. Ash applies multitenancy at query-build and data-layer-prefix time, not inside query.filter, so the evaluated policy carries no tenant condition and a tenant-B notification routed to a tenant-A subscriber is emitted whenever the policy filter is true. The single-notification clause has no tenant guard at all, and the batched clause checks only the head of the notification list, so non-head entries authorize purely in memory. A tenant-scoped read is reached only when filter evaluation fails. This issue affects ash_graphql: from 1.4.0 before 1.11.0.

Affected products

ash-project ash_graphql: from 1.4.0 before 1.11.0 — fixed in 1.11.0

How to fix

Upgrade to a fixed version: ash-project ash_graphql 1.11.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-80223 or the next vulnerability affects your stack