Issues

• Cosine space accepts NaN / +Inf vectors and returns NaN distances that participate in ranking (0.9.0)

  nmslib/hnswlib#687 · Filter by author JoeyLYZ666 opened on Sep 29, 2026

• BFIndex returns the wrong nearest-neighbor order when squared L2 distances overflow float32

  nmslib/hnswlib#686 · Filter by author JoeyLYZ666 opened on Sep 29, 2026

• Cosine-space distances for small-norm vectors are garbage: ±1e10 magnitudes, negative self-distance, far outside [0, 2]

  nmslib/hnswlib#685 · Filter by author JoeyLYZ666 opened on Sep 29, 2026

• Heap-buffer-overflow WRITE in loadIndex() via mismatched max_elements_/cur_element_count (crafted index file)

  nmslib/hnswlib#673 · Filter by author 3nesdeniz opened on Aug 11, 2026

• Possible undefined behavior with arm64

  nmslib/hnswlib#669 · Filter by author jlmelville opened on May 25, 2026

• Multithreading is disabled for small batches what slows down high-dimensional queries (Python bindings)

  nmslib/hnswlib#667 · Filter by author martinloretzzz opened on Apr 26, 2026

• Recommendations for appropriate ef, ef_construction, and M parameters

  nmslib/hnswlib#666 · Filter by author kiplingw opened on Apr 2, 2026

• Integrating TurboQuant vector quantization

  enhancement
  Feature

  nmslib/hnswlib#662 · Filter by author ilyajob05 opened on Mar 27, 2026
  

• [Feature Request] getMemoryUsage()

  nmslib/hnswlib#648 · Filter by author kiplingw opened on Mar 15, 2026
  9

• LeakSanitizer detects alloc-dealloc-mismatch (operator new [] vs operator delete)

  nmslib/hnswlib#645 · Filter by author yushan107 opened on Feb 9, 2026
  1

• Minor optimizations for getDataByLabel?

  nmslib/hnswlib#643 · Filter by author LTLA opened on Jan 28, 2026

• Consider making saveIndex() a const method?

  nmslib/hnswlib#642 · Filter by author LTLA opened on Jan 28, 2026

• [Performance]Provides NEON Optimized Implementations for ARM in HNSWlib

  nmslib/hnswlib#639 · Filter by author AmberLZY opened on Jan 21, 2026
  1

• Request for NEON/SVE Optimized Implementations for ARM in HNSWlib

  nmslib/hnswlib#637 · Filter by author ThatikondV opened on Oct 28, 2025
  1

• Potential Bug: M_ might be used incorrectly instead of Mcurmax in neighbor selection heuristic

  nmslib/hnswlib#635 · Filter by author MarsMan13 opened on Oct 12, 2025
  1

• MEMCHECK: ==1321== 544 bytes in 1 blocks are possibly lost in loss record

  nmslib/hnswlib#627 · Filter by author JohnSmithBH84 opened on Jun 10, 2025

• Use after free, in bruteforce.h

  nmslib/hnswlib#626 · Filter by author davidshoon opened on Jun 6, 2025

• Ensure BFIndex can be extended/resized

  nmslib/hnswlib#624 · Filter by author davnn opened on Apr 19, 2025

• vcvarsall error

  nmslib/hnswlib#622 · Filter by author rsham004 opened on Apr 13, 2025

• Getting High Latency on Small Dataset

  nmslib/hnswlib#618 · Filter by author iamsabhoho opened on Mar 20, 2025
  2

• Requesting Feedback on Adding HNSWLib to Big-ANN-Benchmarks Streaming Track

  nmslib/hnswlib#612 · Filter by author magdalendobson opened on Feb 12, 2025

• Add type annotations

  nmslib/hnswlib#611 · Filter by author lbhm opened on Feb 12, 2025
  1

• The problem of memory overflow when creating many small HNSWs

  nmslib/hnswlib#610 · Filter by author DMoRanSky opened on Jan 25, 2025
  1

• RuntimeError: Cannot return the results in a contiguous 2D array. Probably ef or M is too small

  nmslib/hnswlib#608 · Filter by author esmailoghli opened on Jan 17, 2025

• Would you consider adopting AMX (Advanced Matrix Extensions) to accelerate inner product computations?

  nmslib/hnswlib#607 · Filter by author ruclz opened on Jan 13, 2025