Files
lancedb/docs/web/embedding
Will JonesandClaude Opus 5.5 9020640538 fix(python)!: don't trust embedding settings from table metadata (#4550)
BREAKING CHANGE: `SentenceTransformerEmbeddings.trust_remote_code` now
defaults to `False` (was `True`). When an embedding function is restored
from table metadata, `trust_remote_code=True` and custom endpoints
(OpenAI `base_url`, Ollama `host`/proxy, watsonx `url`) are only honored
if the process approved them; otherwise computing embeddings raises
`UntrustedEmbeddingConfigError`. Functions created in the same process
are approved automatically. To reopen such a table in a new process,
call `get_registry().allow_remote_code(model, revision=...)` or
`get_registry().allow_endpoint(url)` first.

## Summary

Embedding functions are rebuilt from table metadata, which anyone who
can write the table controls. Since sentence-transformers defaulted
`trust_remote_code` to `True`, opening and querying a crafted table ran
arbitrary code from a model repository (GHSA-x8v2-vj73-gfwm). Metadata
could likewise point `base_url` at another server, sending it queries
and the `OPENAI_API_KEY` from the environment.

The table can no longer grant itself trust:

```python
registry = get_registry()
registry.allow_remote_code("nomic-ai/nomic-embed-text-v1.5", revision="<commit>")
registry.allow_endpoint("http://my-ollama-host:11434")
```

Trust is keyed by model name (optionally pinned to a revision), so
approving one model doesn't let a table swap in another. Restored
functions that aren't approved are replaced by a placeholder that raises
on use without constructing the real function (`huggingface` loads its
model in `__init__`), so non-embedding operations on the table keep
working. `sentence-transformers` and `huggingface` gain a `revision`
parameter. Custom embedding functions can opt in by overriding the new
`remote_code_model()` / `endpoints()` hooks.

Not covered: TypeScript (its built-ins have neither remote code nor
configurable endpoints), Bedrock `assumed_role`, and third-party
functions that don't implement the hooks.

## Evidence

`test_embeddings_trust.py` covers restore with and without approval,
revision pinning, swapped model names, endpoint gating, and that the
table stays usable. Opening a table with crafted metadata and searching
it now gives:

```
UntrustedEmbeddingConfigError: Embedding function 'sentence-transformers' was restored from table metadata with settings this process has not approved:
  - runs code from model 'attacker/model' at revision None. If you trust it, call get_registry().allow_remote_code('attacker/model', revision=None)
```

## Merge Risk

**Door:** One-way: changes a default and makes previously working
reopen-and-search flows require explicit approval.
**Blast Radius:** public-api (Python embeddings); users of remote-code
models or custom endpoints who reopen tables in a new process.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-19 12:11:25 -07:00
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