diff --git a/external-libs/android32.Dockerfile b/external-libs/android32.Dockerfile
index 0746f9de..6df797e7 100644
--- a/external-libs/android32.Dockerfile
+++ b/external-libs/android32.Dockerfile
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.3
-ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
+ENV ZLIB_VERSION 1.3.1
+ENV ZLIB_HASH 9a93b2b7dfdac77ceba5a558a580e74667dd6fede4585b91eefb60f03b72df23
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \
diff --git a/external-libs/android32_x86.Dockerfile b/external-libs/android32_x86.Dockerfile
index 5271181a..4eb18e0a 100644
--- a/external-libs/android32_x86.Dockerfile
+++ b/external-libs/android32_x86.Dockerfile
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.3
-ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
+ENV ZLIB_VERSION 1.3.1
+ENV ZLIB_HASH 9a93b2b7dfdac77ceba5a558a580e74667dd6fede4585b91eefb60f03b72df23
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \
diff --git a/external-libs/android64.Dockerfile b/external-libs/android64.Dockerfile
index e7a6c731..7e2ca0e8 100644
--- a/external-libs/android64.Dockerfile
+++ b/external-libs/android64.Dockerfile
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.3
-ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
+ENV ZLIB_VERSION 1.3.1
+ENV ZLIB_HASH 9a93b2b7dfdac77ceba5a558a580e74667dd6fede4585b91eefb60f03b72df23
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \
diff --git a/external-libs/android64_x86.Dockerfile b/external-libs/android64_x86.Dockerfile
index 500e09e0..9d287df2 100644
--- a/external-libs/android64_x86.Dockerfile
+++ b/external-libs/android64_x86.Dockerfile
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.3
-ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
+ENV ZLIB_VERSION 1.3.1
+ENV ZLIB_HASH 9a93b2b7dfdac77ceba5a558a580e74667dd6fede4585b91eefb60f03b72df23
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \