Answer in brief
CVE-2026-124959 records a Unknown severity vulnerability in Nmaslib Hnswlib and Spotify Voyager HNSW Index Deserialization Heap Out-of-Bounds Write. The current sources do not mark it as known exploited. The current feed maps hnswlib/hnswlib (generic), Spotify/Voyager (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps hnswlib/hnswlib (generic), Spotify/Voyager (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| hnswlib/hnswlibgeneric | >=0.5.0 <=0.9.0 | Not reported |
| Spotify/Voyagergeneric | >=2.0.7 <=2.1.1 | Not reported |
Published upstream
Nov 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 9, 2026
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.
Quoted source text, attributed separately from HOL analysis.