The loadIndex function in nmslib hnswlib and Spotify Voyager does not verify that the element count in a serialized HNSW index is within the stored capacity used to allocate the heap buffer. An attacker can supply a crafted index file with an element count greater than the stored capacity, causing the loader to write beyond the allocated buffer and potentially crash the application when it loads the file.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Spotify | Voyager | affected |
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| hnswlib | hnswlib | affected |
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Fixes
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References
History
Mon, 09 Nov 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | The loadIndex function in nmslib hnswlib and Spotify Voyager does not verify that the element count in a serialized HNSW index is within the stored capacity used to allocate the heap buffer. An attacker can supply a crafted index file with an element count greater than the stored capacity, causing the loader to write beyond the allocated buffer and potentially crash the application when it loads the file. | |
| Title | Nmaslib Hnswlib and Spotify Voyager HNSW Index Deserialization Heap Out-of-Bounds Write | |
| References |
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MITRE
Status: PUBLISHED
Assigner: certcc
Published:
Updated: 2026-11-09T15:04:38.649Z
Reserved: 2026-11-09T15:02:37.082Z
Link: CVE-2026-124959
Vulnrichment
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NVD
Status : Received
Published: 2026-11-09T15:17:19.357
Modified: 2026-11-09T15:17:19.357
Link: CVE-2026-124959
Redhat
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OpenCVE Enrichment
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Weaknesses
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