diff --git a/build.gradle b/build.gradle
index fecbbacee..1df5c90c4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -158,8 +158,8 @@ dependencies {
     implementation 'org.apache.commons:commons-compress:1.26.0'
     implementation 'org.apache.commons:commons-io:2.15.1'
 
-    implementation 'org.bouncycastle:bcpkix-jdk18on:1.71'
-    implementation 'org.bouncycastle:bcprov-jdk18on:1.71'
+    implementation 'org.bouncycastle:bcpkix-jdk18on:1.77'
+    implementation 'org.bouncycastle:bcprov-jdk18on:1.77'
 
     implementation 'org.ow2.asm:asm:9.6'
     implementation 'org.ow2.asm:asm-commons:9.6'
diff --git a/build.xml b/build.xml
index e9a365922..7b733a643 100644
--- a/build.xml
+++ b/build.xml
@@ -851,8 +851,8 @@ The text for an official release would continue like ...
             <zipfileset src="extlibs/asm-commons-9.6.jar" excludes="module-info.class"/>
             <zipfileset src="extlibs/asm-util-9.6.jar" excludes="module-info.class"/>
             <rule pattern="org.objectweb.asm.**" result="org.python.objectweb.asm.@1"/>
-            <zipfileset src="extlibs/bcpkix-jdk18on-1.71.jar" excludes="META-INF/**"/>
-            <zipfileset src="extlibs/bcprov-jdk18on-1.71.jar" excludes="META-INF/**"/>
+            <zipfileset src="extlibs/bcpkix-jdk18on-1.77.jar" excludes="META-INF/**"/>
+            <zipfileset src="extlibs/bcprov-jdk18on-1.77.jar" excludes="META-INF/**"/>
             <rule pattern="org.bouncycastle.**" result="org.python.bouncycastle.@1"/>
             <zipfileset src="extlibs/commons-compress-1.26.0.jar"/>
             <rule pattern="org.apache.commons.compress.**" result="org.python.apache.commons.compress.@1"/>
diff --git a/extlibs/bcpkix-jdk18on-1.71.jar b/extlibs/bcpkix-jdk18on-1.71.jar
deleted file mode 100644
index e2f51bd24..000000000
Binary files a/extlibs/bcpkix-jdk18on-1.71.jar and /dev/null differ
diff --git a/extlibs/bcpkix-jdk18on-1.77.jar b/extlibs/bcpkix-jdk18on-1.77.jar
new file mode 100644
index 000000000..e8b6021a2
Binary files /dev/null and b/extlibs/bcpkix-jdk18on-1.77.jar differ
diff --git a/extlibs/bcprov-jdk18on-1.71.jar b/extlibs/bcprov-jdk18on-1.77.jar
similarity index 51%
rename from extlibs/bcprov-jdk18on-1.71.jar
rename to extlibs/bcprov-jdk18on-1.77.jar
index c99673014..651d2fba5 100644
Binary files a/extlibs/bcprov-jdk18on-1.71.jar and b/extlibs/bcprov-jdk18on-1.77.jar differ