CVE-2026-85664 PUBLISHED

Chroma 1.5.9 fails to validate maximum bounds on HNSW index parameters max_neighbors, ef_construction, and ef_search in collection-create requests. Unauthenticated attackers can supply arbitrarily large parameter values to exhaust server memory and cause denial of service during index compaction.

• George Chen finder

• GitHub Issue #7225
• https://github.com/chroma-core/chroma
• https://github.com/chroma-core/chroma/blob/1.5.9/rust/types/src/hnsw_configuration.rs
• https://github.com/chroma-core/chroma/blob/1.5.9/rust/frontend/src/auth/mod.rs
• VulnCheck Advisory: Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion

• Allocation of Resources Without Limits or Throttling CWE