{"id":"CVE-2026-85664","aliases":["EUVD-2026-71120","GHSA-3q9g-fh5w-hp67"],"status":"published","title":"Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion","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.","severity":{"version":"4.0","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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00658,"percentile":0.51771,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-770"],"published":"2026-09-04T14:32:20Z","modified":"2026-10-28T02:30:54Z","products":[{"vendor":"chroma-core","product":"chroma"},{"vendor":"themerex","product":"chroma"}],"references":[{"url":"https://github.com/chroma-core/chroma/issues/7225","tags":["issue-tracking","report"]},{"url":"https://github.com/chroma-core/chroma","tags":["product","package"]},{"url":"https://github.com/chroma-core/chroma/blob/1.5.9/rust/types/src/hnsw_configuration.rs","tags":["technical-description","article"]},{"url":"https://github.com/chroma-core/chroma/blob/1.5.9/rust/frontend/src/auth/mod.rs","tags":["technical-description","article"]},{"url":"https://www.vulncheck.com/advisories/chroma-1.5.9-unbounded-hnsw-index-parameters-memory-exhaustion","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85664","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-3q9g-fh5w-hp67"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85664.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-85664","title":"Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion","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.","status":"published","published":"2026-09-04T14:32:20.917Z","modified":"2026-09-10T15:08:14.501Z","cvss":[{"version":"4.0","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","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:19:52.773089Z"}],"euvd":[{"id":"EUVD-2026-71120","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.","status":"published","published":"2026-09-04T14:32:20Z","modified":"2026-09-10T15:08:14Z","cvss":[{"version":"4.0","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","level":"high"}],"updated_at":"2026-11-02T17:28:24.501469Z"}],"ghsa":[{"id":"GHSA-3q9g-fh5w-hp67","title":"Chroma 1.5.9 fails to validate maximum bounds on HNSW index parameters max_neighbors,...","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.","status":"published","published":"2026-09-04T15:36:14Z","modified":"2026-09-04T15:36:24Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:11:22.550434Z"}],"nvd":[{"id":"CVE-2026-85664","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.","status":"published","published":"2026-09-04T15:17:44.097Z","modified":"2026-09-10T16:18:00.51Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:43.737972Z"}],"osv":[{"id":"CVE-2026-85664","title":"Chroma 1.5.9 Unbounded HNSW Index Parameters Memory Exhaustion","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.","status":"published","published":"2026-09-04T14:32:20.917Z","modified":"2026-10-28T02:30:54.456332474Z","cvss":[{"version":"4.0","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","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:45:18.825071Z"}]}}