Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion
Priority MEDIUM 45CWE-770Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00658 51st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| chroma-core | chroma | up to 1.5.9 | — | No fix listed | CNA |
- chroma Vendorchroma-core Affected up to 1.5.9 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-85664
- 2026-10-03 Alias added: GHSA-3q9g-fh5w-hp67
- 2026-10-11 EPSS moved to the 50th–90th percentile
References
More chroma-core vulnerabilities
- TI-2026-62523 Chroma through 1.5.9 Authorization Bypass via Collection Identifier CVSS 4.0HIGH 8.6
Sources
- CVE-2026-85664 · CVE Program
- CVE-2026-85664 · NVD
- FIRST EPSS
- GHSA-3q9g-fh5w-hp67 · GitHub Advisory Database · CC BY 4.0
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