Resource exhaustion in Chroma-Core Chroma
CVE-2026-85664
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (50.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003
Affected products
Weakness classification (CWE)
References
- github.com/chroma-core/chroma (product)
- github.com/chroma-core/chroma/blob/1.5.9/rust/frontend/src/auth/mod.rs (technical-description)
- github.com/chroma-core/chroma/blob/1.5.9/rust/types/src/hnsw_configuration.rs (technical-description)
- github.com/chroma-core/chroma/issues/7225 (issue-tracking)
- www.vulncheck.com/advisories/chroma-1.5.9-unbounded-hnsw-index-parameters-memor… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-85664?
- CVE-2026-85664 is a high-severity vulnerability in Chroma-Core Chroma, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-09-04.
- How severe is CVE-2026-85664?
- High severity. CVSS v3 base score is 7.5 out of 10.