Update protobuf version

diff --git a/java/bom/pom.xml b/java/bom/pom.xml
index af2d702..c8a92e4 100644
--- a/java/bom/pom.xml
+++ b/java/bom/pom.xml

@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-bom</artifactId>
-  <version>3.15.6</version>
+  <version>3.15.7</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [BOM]</name>

diff --git a/java/core/pom.xml b/java/core/pom.xml
index 4df7d43..0176b9f 100644
--- a/java/core/pom.xml
+++ b/java/core/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.15.6</version>
+    <version>3.15.7</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>

diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index 021eac0..d60a480 100644
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.15.6</version>
+    <version>3.15.7</version>
   </parent>
 
   <artifactId>protobuf-javalite</artifactId>

diff --git a/java/pom.xml b/java/pom.xml
index f6b1883..b7669d0 100644
--- a/java/pom.xml
+++ b/java/pom.xml

@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.15.6</version>
+  <version>3.15.7</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>

diff --git a/java/util/pom.xml b/java/util/pom.xml
index 37d7c0f..5899979 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.15.6</version>
+    <version>3.15.7</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>