CVE-2026-81636Query-complexity limit bypass via first/last pagination arguments in AshGraphql enables denial of service

Official description

Allocation of Resources Without Limits or Throttling vulnerability in ash-project ash_graphql allows an unauthenticated client to bypass the configured GraphQL query-complexity limit and force an unbounded database read. AshGraphql.Graphql.Resolver.query_complexity/3 multiplies child complexity by the requested page size only when the argument map contains :limit (offset pagination). Relay connections and keyset pagination use first and last, which never match that clause and fall through to the catch-all that returns child_complexity + 1. A nested relay query such as posts(first: 500) { edges { node { comments(first: 500) { ... } } } } therefore scores as trivially cheap while materializing the full fan-out, passing an Absinthe max_complexity cap that rejects the equivalent limit-based query. The fix adds first and last clauses clamped to the action's page size. This issue affects ash_graphql: from 0.16.23 before 1.11.0.

Affected products (as reported)

References

• https://github.com/ash-project/ash_graphql/security/advisories/GHSA-mwc4-r9fc-h6mg vendor-advisory, related
• https://cna.erlef.org/cves/CVE-2026-81636.html related
• https://osv.dev/vulnerability/EEF-CVE-2026-81636 related
• https://github.com/ash-project/ash_graphql/commit/c3229f6a65cbabb32fd7ffcac881922d1b3b30ad patch