AWS Amplify CVE-2026-108096

Exploitation requires an authenticated account on the target application (PR:L) AND that the application's backend was generated by @aws-amplify/graphql-index-transformer before 3.1.2 using owner-scoped secondary-index (@index) query resolvers with per-user authorization. The flaw is reached by sending crafted queries against those generated index resolvers over the network. Limiting factors: the attacker must be a valid user of the same application, impact is confined to reading other users' records within that app (no write/integrity or availability effect), and applications not using the vulnerable owner-authorized index resolvers - or already upgraded/redeployed to 3.1.2+ (including forked or derivative resolver code) - are not exposed.

This is a genuine but moderate-priority authorization flaw (CWE-639, Authorization Bypass Through User-Controlled Key), not an inflated high-CVSS issue. The vendor CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N) scores 7.1 and is internally consistent with the description: a network-reachable GraphQL API, low attack complexity, and a required low-privilege authenticated account, yielding high confidentiality impact (cross-tenant data read) with no integrity or availability impact. No EPSS score, no CISA KEV listing, and no public POC were provided in the intelligence, so there is no public exploit identified at time of analysis and no evidence of active exploitation - the risk is driven by the structural ease of exploitation (any authenticated app user can craft queries against affected index resolvers) rather than by observed in-the-wild activity. The key limiting factor is that the attacker must already be an authenticated user of the same application and the application must have been built with vulnerable owner-scoped secondary-index resolvers from @aws-amplify/graphql-index-transformer before 3.1.2; this confines impact to confidential data of co-tenants rather than full compromise. One data-quality note: the input Tag 'Authentication Bypass' conflicts with the description and CWE - this is an authorization (access-control) bypass by an already-authenticated user, not an authentication bypass.

An attacker registers or uses an existing low-privilege account in a multi-tenant application whose backend was generated by @aws-amplify/graphql-index-transformer before 3.1.2. They send crafted GraphQL queries against secondary-index resolvers whose owner-based authorization checks are improperly enforced, returning records belonging to other users of the same application. No public exploit code was identified, and the low attack complexity (AC:L) means no special timing or configuration beyond a valid account is needed.