[ES|QL] IN operator fails when used with array or query param pointing to array #136998
Description
Elasticsearch Version
9.2.0 (or latest)
Installed Plugins
No response
Java Version
bundled
OS Version
MacBook-Pro.local 23.6.0 Darwin Kernel Version 23.6.0: Mon Aug 11 21:20:40 PDT 2025; root:xnu-10063.141.1.706.13~1/RELEASE_ARM64_T6020 arm64
Problem Description
When using the IN operator in an ES|QL query with a list, either inline or passed via query parameters, Elasticsearch fails with a class_cast_exception (500 HTTP).
Steps to Reproduce
FROM search-movies
| WHERE id IN (["1", "2"])
Or with param
FROM search-movies
| WHERE id IN (?param)
{
"param": ["1", "2"]
}
Logs (if relevant)
Full response from ES
#! No limit defined, adding default limit of [1000]
{
"error": {
"root_cause": [
{
"type": "class_cast_exception",
"reason": "class java.util.ImmutableCollections$ListN cannot be cast to class org.apache.lucene.util.BytesRef (java.util.ImmutableCollections$ListN is in module java.base of loader 'bootstrap'; org.apache.lucene.util.BytesRef is in module org.apache.lucene.core@10.3.1 of loader 'app')"
}
],
"type": "class_cast_exception",
"reason": "class java.util.ImmutableCollections$ListN cannot be cast to class org.apache.lucene.util.BytesRef (java.util.ImmutableCollections$ListN is in module java.base of loader 'bootstrap'; org.apache.lucene.util.BytesRef is in module org.apache.lucene.core@10.3.1 of loader 'app')"
},
"status": 500
}