diff --git a/build.gradle b/build.gradle
index 8a335ec893..83a195fe5b 100644
--- a/build.gradle
+++ b/build.gradle
@@ -119,7 +119,7 @@ subprojects {
         commonsIoVersion = '2.11.0'
         commonsMathVersion = '3.6.1'
         junitVersion = '5.8.2'
-        log4jVersion = '2.14.1'
+        log4jVersion = '2.15.0'
         mockitoVersion = '4.1.0'
         hamcrestVersion = '2.2'
         xmlbeansVersion = '5.0.2'
diff --git a/build.xml b/build.xml
index f58c184acd..ee18011c4c 100644
--- a/build.xml
+++ b/build.xml
@@ -268,7 +268,7 @@ under the License.
     <dependency prefix="main.commons-math3" artifact="org.apache.commons:commons-math3:3.6.1" usage="main"/>
     <dependency prefix="main.commons-io" artifact="commons-io:commons-io:2.11.0" usage="main"/>
     <dependency prefix="main.com.zaxxer" artifact="com.zaxxer:SparseBitSet:1.2" usage="main"/>
-    <dependency prefix="main.log4j-api" artifact="org.apache.logging.log4j:log4j-api:2.14.1" usage="main"/>
+    <dependency prefix="main.log4j-api" artifact="org.apache.logging.log4j:log4j-api:2.15.0" usage="main"/>
 
     <dependency prefix="main.junit-api" artifact="org.junit.jupiter:junit-jupiter-api:5.8.2" usage="main-tests"/>
     <dependency prefix="main.junit-jengine" artifact="org.junit.jupiter:junit-jupiter-engine:5.8.2" usage="main-tests"/>
@@ -288,7 +288,7 @@ under the License.
     <dependency prefix="main.byte-buddy" artifact="net.bytebuddy:byte-buddy:1.12.3" usage="main-tests"/>
     <dependency prefix="main.byte-buddy-agent" artifact="net.bytebuddy:byte-buddy-agent:1.12.3" usage="main-tests"/>
     <dependency prefix="main.objenesis" artifact="org.objenesis:objenesis:3.1" usage="main-tests"/>
-    <dependency prefix="main.log4j-core" artifact="org.apache.logging.log4j:log4j-core:2.14.1" usage="main-tests"/>
+    <dependency prefix="main.log4j-core" artifact="org.apache.logging.log4j:log4j-core:2.15.0" usage="main-tests"/>
     <dependency prefix="main.commons-logging" artifact="commons-logging:commons-logging:1.2" usage="main-tests"/>
 
     <dependency prefix="main.ant" artifact="org.apache.ant:ant:1.10.9" usage="excelant"/>
@@ -690,9 +690,7 @@ under the License.
                 <include name="xmlbeans-5.0.1.jar"/>
             </fileset>
             <fileset dir="${basedir}/lib/ooxml-provided">
-                <include name="bc*-1.65.jar"/>
-                <include name="bc*-1.66.jar"/>
-                <include name="bc*-1.68.jar"/>
+                <include name="bc*-1.6*.jar"/>
                 <include name="batik*.jar"/>
                 <include name="slf4j*-1.7.30.jar"/>
                 <include name="xmlsec-2.2*.jar"/>
@@ -2579,9 +2577,9 @@ under the License.
         <dependency prefix="spotbugs.commons-text" artifact="org.apache.commons:commons-text:1.9" usage="${spotbugs.lib}"/>
         <dependency prefix="spotbugs.jcip-annotations" artifact="net.jcip:jcip-annotations:1.0" usage="${spotbugs.lib}"/>
         <dependency prefix="spotbugs.icu4j" artifact="com.ibm.icu:icu4j:68.2" usage="${spotbugs.lib}" target="icu4j-63.1.jar"/>
-        <dependency prefix="spotbugs.log4j-api" artifact="org.apache.logging.log4j:log4j-api:2.14.0" usage="${spotbugs.lib}"/>
-        <dependency prefix="spotbugs.log4j-core" artifact="org.apache.logging.log4j:log4j-core:2.14.0" usage="${spotbugs.lib}"/>
-        <dependency prefix="spotbugs.log4j-slf4j18-impl" artifact="org.apache.logging.log4j:log4j-slf4j18-impl:2.14.0" usage="${spotbugs.lib}"/>
+        <dependency prefix="spotbugs.log4j-api" artifact="org.apache.logging.log4j:log4j-api:2.15.0" usage="${spotbugs.lib}"/>
+        <dependency prefix="spotbugs.log4j-core" artifact="org.apache.logging.log4j:log4j-core:2.15.0" usage="${spotbugs.lib}"/>
+        <dependency prefix="spotbugs.log4j-slf4j18-impl" artifact="org.apache.logging.log4j:log4j-slf4j18-impl:2.15.0" usage="${spotbugs.lib}"/>
         <dependency prefix="spotbugs.saxon" artifact="net.sf.saxon:Saxon-HE:9.9.1-8" usage="${spotbugs.lib}"/>
 
         <mkdir dir="${basedir}${spotbugs.lib}/config"/>
diff --git a/osgi/pom.xml b/osgi/pom.xml
index c44ead564c..a2000fcced 100644
--- a/osgi/pom.xml
+++ b/osgi/pom.xml
@@ -231,7 +231,7 @@
         <dependency>
             <groupId>org.apache.logging.log4j</groupId>
             <artifactId>log4j-core</artifactId>
-            <version>2.14.0</version>
+            <version>2.15.0</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/poi-ooxml/src/main/java/org/apache/poi/poifs/crypt/dsig/SignatureInfo.java b/poi-ooxml/src/main/java/org/apache/poi/poifs/crypt/dsig/SignatureInfo.java
index 98347ef578..f90bf17bb0 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/poifs/crypt/dsig/SignatureInfo.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/poifs/crypt/dsig/SignatureInfo.java
@@ -153,9 +153,9 @@ import org.w3c.dom.events.MutationEvent;
  * <p>To use SignatureInfo and its sibling classes, you'll need to have the following libs
  * in the classpath:</p>
  * <ul>
- * <li>BouncyCastle bcpkix and bcprov (tested against 1.67)</li>
- * <li>Apache Santuario "xmlsec" (tested against 2.2.0)</li>
- * <li>and log4j-api (tested against 2.14.0)</li>
+ * <li>BouncyCastle bcpkix and bcprov (tested against 1.70)</li>
+ * <li>Apache Santuario "xmlsec" (tested against 2.3.0)</li>
+ * <li>and log4j-api (tested against 2.15.0)</li>
  * </ul>
  */
 public class SignatureInfo {