CVE-2026-85664

Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion

Published Sep 4, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Chroma-core
Chroma-core chroma
Vendors & Products Chroma-core
Chroma-core chroma
Type Values Removed Values Added
Description 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.
Title Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 10, 2026, 3:08 PM
Reserved
Sep 4, 2026, 1:32 PM
Status
Deferred
Published
Sep 4, 2026, 3:17 PM
Modified
Sep 10, 2026, 4:18 PM
Severity
Important
Public date
Sep 4, 2026, 2:32 PM