diff --git a/README.md b/README.md
index f83f8cea0..f6de120be 100644
--- a/README.md
+++ b/README.md
@@ -98,22 +98,25 @@ The framework serves two distinct, but related use cases:
 ### Version compatibility with Elasticsearch
 
 > [!NOTE]
-> Version compatibility will not be checked if Elasticsearch is serverless.
-
-The Connector will perform a version compatibility check with the configured Elasticsearch server on startup.
-If the versions are incompatible, the Connector will terminate and output the incompatible versions in the shell.
-If the versions are different but otherwise compatible, the Connector will output a warning in the shell but will continue operating.
-
-We recommend running on the same version as Elasticsearch.
-However, if you want to hold back upgrading one or the other for any reason, use this table to determine if your versions will be compatible.
-
-| Situation                       | Example Connector Framework version | Example ES version | Outcome |
-|---------------------------------|-------------------------------------|--------------------| ------- |
-| Versions are the same.          | 8.15.1.0                            | 8.15.1             | 💚 OK      |
-| Connectors has a build version. | 8.15.1.3                            | 8.15.1             | 💚 OK      |
-| ES patch number is newer.       | 8.15.__0__.0                        | 8.15.__1__         | ⚠️ Logged warning      |
-| ES minor number is newer.       | 8.__14__.2.0                        | 8.__15__.0         | ⚠️ Logged warning      |
-| ES major number is newer.       | __8__.15.1.0                        | __9__.0.0          | 🚫 Fatal error      |
-| ES patch number is older.       | 8.15.__1__.0                        | 8.15.__0__         | ⚠️ Logged warning      |
-| ES minor number is older.       | 8.__15__.1.0                        | 8.__14__.2         | 🚫 Fatal error      |
-| ES major number is older.       | __9__.0.0.0                         | __8__.15.1         | 🚫 Fatal error      |
+> Version compatibility is not checked when Elasticsearch is **serverless** (the connector service skips the check on startup).
+
+The connector service compares its version to the configured Elasticsearch server on startup.
+If the versions are incompatible, the service exits and logs the mismatch.
+If the versions differ but are compatible, the service logs a warning and continues.
+
+We recommend running the connector service on the same stack version as Elasticsearch.
+Use this table to decide whether a deliberate version skew is supported.
+
+Do **not downgrade** the connector service to an older release than the one used when connectors were created.
+If you downgrade anyway, connector configuration stored in Elasticsearch may no longer match what the older service expects — you may need to **recreate** affected connectors.
+
+| Situation | Example connector version | Example ES version | Outcome |
+|-----------|---------------------------|--------------------|---------|
+| Versions match | 8.15.1.0 | 8.15.1 | OK |
+| Connector has a build suffix | 8.15.1.3 | 8.15.1 | OK |
+| ES patch is newer | 8.15.__0__.0 | 8.15.__1__ | Warning |
+| ES minor is newer | 8.__14__.2.0 | 8.__15__.0 | Warning |
+| ES major is newer | __8__.15.1.0 | __9__.0.0 | Fatal error |
+| ES patch is older | 8.15.__1__.0 | 8.15.__0__ | Warning |
+| ES minor is older | 8.__15__.1.0 | 8.__14__.2 | Fatal error |
+| ES major is older | __9__.0.0.0 | __8__.15.1 | Fatal error |
diff --git a/app/connectors_service/NOTICE.txt b/app/connectors_service/NOTICE.txt
index a8acf13e1..8d98e35b9 100644
--- a/app/connectors_service/NOTICE.txt
+++ b/app/connectors_service/NOTICE.txt
@@ -4241,7 +4241,7 @@ Apache Software License
 
 
 google-auth
-2.59.1
+2.60.0
 Apache Software License
                                  Apache License
                            Version 2.0, January 2004
@@ -7114,7 +7114,7 @@ THE SOFTWARE.
 
 
 pyspnego
-0.12.3
+0.12.4
 MIT
 MIT License
 
diff --git a/docs/UPGRADING.md b/docs/UPGRADING.md
index bb1519aca..bdfdf04a9 100644
--- a/docs/UPGRADING.md
+++ b/docs/UPGRADING.md
@@ -33,6 +33,9 @@ As Elastic adds new features to the framework, internal classes are renamed, mov
 Periodically, the [connector protocol](./CONNECTOR_PROTOCOL.md) changes.
 If you find a change that needs to be made at the framework level, [submit a PR](./CONTRIBUTING.md#pull-request-etiquette) for the fix, so that your branch does not differ from the Elastic-maintained remote.
 
+### Version compatibility with Elasticsearch
+See [Version compatibility with Elasticsearch](../README.md#version-compatibility-with-elasticsearch) in the repository README (including serverless and supported version skew). Do not downgrade the connector service below the version used when connectors were configured.
+
 ### Upgrade all stack components beforehand
 Before upgrading `connectors`, you should first stop your running connectors services, upgrade-and-start Elasticsearch, upgrade-and-start Enterprise Search, upgrade-and-start Kibana, and only then upgrade-and-start `connectors`.
 As a part of Enterprise Search, the connectors framework's data migrations live inside Enterprise Search.