Add release notes for Gerrit v2.16.26

Change-Id: I15ba3c269f4adfa6281837481c4eeec46bf64487
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index 8b3063c..5b972d6 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -6,7 +6,8 @@
 toc: true
 ---
 
-Download: **[2.16.25](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.25.war)**
+Download: **[2.16.26](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.26.war)**
+| [2.16.25](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.25.war)
 | [2.16.23](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.23.war)
 | [2.16.22](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.22.war)
 | [2.16.21](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.21.war)
@@ -32,7 +33,8 @@
 | [2.16.1](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.1.war)
 | [2.16](https://gerrit-releases.storage.googleapis.com/gerrit-2.16.war)
 
-Documentation: **[2.16.25](https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.25/index.html)**
+Documentation: **[2.16.26](https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.26/index.html)**
+| [2.16.25](https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.25/index.html)
 | [2.16.23](https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.23/index.html)
 | [2.16.22](https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.22/index.html)
 | [2.16.21](https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.21/index.html)
@@ -638,6 +640,23 @@
 
 ## Bugfix Releases
 
+### 2.16.26
+
+* Security Fixes
+
+  * [Issue 13858](https://bugs.chromium.org/p/gerrit/issues/detail?id=13858)
+    [CVE-2021-22553](https://nvd.nist.gov/vuln/detail/CVE-2021-22553):
+  Fixed memory leak in Git-over-HTTP requests.
+
+    Unauthenticated users could exploit this problem in a Denial of Service attack,
+    causing the server to go out-of-memory.
+
+* Dependency Updates
+
+  * Update JGit to 5.1.15.202012011955-r.
+
+  * Update testcontainers to 1.15.0.
+
 ### 2.16.25
 
 * Security Fixes