diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index e1361e08..9d48af7e 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "9.18.2"
+  ".": "9.18.3"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98401abf..68c5b72e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 All notable changes to the LaunchDarkly Python SDK will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+## [9.18.3](https://github.com/launchdarkly/python-server-sdk/compare/9.18.2...9.18.3) (2026-10-20)
+
+
+### Bug Fixes
+
+* Require certifi 2026.10.19 or newer ([#544](https://github.com/launchdarkly/python-server-sdk/issues/544)) ([518819d](https://github.com/launchdarkly/python-server-sdk/commit/518819dfe176357ef9441bbdf0bebe876f6b11ee))
+
 ## [9.18.2](https://github.com/launchdarkly/python-server-sdk/compare/9.18.1...9.18.2) (2026-10-12)
 
 
diff --git a/PROVENANCE.md b/PROVENANCE.md
index 01c38977..5cd9ba6d 100644
--- a/PROVENANCE.md
+++ b/PROVENANCE.md
@@ -9,7 +9,7 @@ To verify build provenance attestations, we recommend using the [GitHub CLI `att
 <!-- x-release-please-start-version -->
 ```
 # Set the version of the SDK to verify
-SDK_VERSION=9.18.2
+SDK_VERSION=9.18.3
 ```
 <!-- x-release-please-end -->
 
diff --git a/ldclient/version.py b/ldclient/version.py
index 21d0733b..f63a40e5 100644
--- a/ldclient/version.py
+++ b/ldclient/version.py
@@ -1 +1 @@
-VERSION = "9.18.2"  # x-release-please-version
+VERSION = "9.18.3"  # x-release-please-version
diff --git a/pyproject.toml b/pyproject.toml
index b48f8169..3e2bcd6d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "launchdarkly-server-sdk"
-version = "9.18.2"
+version = "9.18.3"
 description = "LaunchDarkly SDK for Python"
 authors = [
     {name = "LaunchDarkly", email = "dev@launchdarkly.com"}