diff --git a/detection_rules/rule_validators.py b/detection_rules/rule_validators.py
index 9b3f412c885..cdfddcb365b 100644
--- a/detection_rules/rule_validators.py
+++ b/detection_rules/rule_validators.py
@@ -924,10 +924,21 @@ def remote_validate_rule(  # noqa: PLR0913
         # mismatch error, as the EsqlSchemaError and EsqlSyntaxError errors from the stack
         # will not be impacted by the difference in schema type mapping.
         mappings_lookup: dict[str, dict[str, Any]] = {stack_version: combined_mappings}
-        versions = get_stack_versions()
-        for version in versions:
+        # Skip stacks below the rule's floor: it is never backported there, and resolving an older
+        # integration package that predates the rule's data sources raises a spurious
+        # EsqlUnknownIndexError. No floor means validate every supported stack, as before. We do not
+        # skip the error at/above the floor; there it correctly flags an unreleasable floor.
+        min_stack = (
+            Version.parse(metadata.min_stack_version, optional_minor_and_patch=True)
+            if metadata.min_stack_version
+            else None
+        )
+        for version in get_stack_versions():
             if version in mappings_lookup:
                 continue
+            if min_stack is not None and Version.parse(version) < min_stack:
+                self.log(f"Skipping {version} stack: below rule min_stack_version {min_stack}")
+                continue
             _, _, combined_mappings = prepare_mappings(
                 elastic_client, indices, event_dataset_integrations, metadata, version, self.log
             )