diff --git a/ports/libressl/aarch64-windows.diff b/ports/libressl/aarch64-windows.diff
new file mode 100644
index 0000000000..a1cbe9a5a3
--- /dev/null
+++ b/ports/libressl/aarch64-windows.diff
@@ -0,0 +1,42 @@
+diff --git a/crypto/arch/aarch64/crypto_cpu_caps_windows.c b/crypto/arch/aarch64/crypto_cpu_caps_windows.c
+new file mode 100644
+index 0000000..e7cdded
+--- /dev/null
++++ b/crypto/arch/aarch64/crypto_cpu_caps_windows.c
+@@ -0,0 +1,36 @@
++/* $OpenBSD: crypto_cpu_caps.c,v 1.2 2024/11/12 13:52:31 jsing Exp $ */
++/*
++ * Copyright (c) 2025 Brent Cook <bcook@openbsd.org>
++ *
++ * Permission to use, copy, modify, and distribute this software for any
++ * purpose with or without fee is hereby granted, provided that the above
++ * copyright notice and this permission notice appear in all copies.
++ *
++ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
++ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
++ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
++ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
++ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
++ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
++ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
++ */
++
++#include <windows.h>
++
++#include "crypto_arch.h"
++
++/* Machine dependent CPU capabilities. */
++uint64_t crypto_cpu_caps_aarch64;
++
++void
++crypto_cpu_caps_init(void)
++{
++	crypto_cpu_caps_aarch64 = 0;
++
++	if (IsProcessorFeaturePresent(PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE)) {
++		crypto_cpu_caps_aarch64 |= CRYPTO_CPU_CAPS_AARCH64_AES;
++		crypto_cpu_caps_aarch64 |= CRYPTO_CPU_CAPS_AARCH64_PMULL;
++		crypto_cpu_caps_aarch64 |= CRYPTO_CPU_CAPS_AARCH64_SHA1;
++		crypto_cpu_caps_aarch64 |= CRYPTO_CPU_CAPS_AARCH64_SHA2;
++	}
++}
diff --git a/ports/libressl/portfile.cmake b/ports/libressl/portfile.cmake
index 317576dd6d..73b7220bde 100644
--- a/ports/libressl/portfile.cmake
+++ b/ports/libressl/portfile.cmake
@@ -7,7 +7,7 @@ vcpkg_download_distfile(
     URLS "https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/${PORT}-${VERSION}.tar.gz"
          "https://github.com/libressl/portable/releases/download/v${VERSION}/${PORT}-${VERSION}.tar.gz"
     FILENAME "${PORT}-${VERSION}.tar.gz"
-    SHA512 01c74c6cafc4274f2c1c2c88b897f2f21eafa4ccdd952dae72065366032ec5efdefbb4f809bca66da5b2f2cef426cf378181ae13c2daf7f3dcc67fab7daf9d51
+    SHA512 b06eccff7b332da38efbc5a039d8ee54bd26437f3d5957f59ac2d93b4464f181c9a665a2c957272be5d9f91f447720f6dfa29b4b72407279ac8a7722c322dac0
 )
 
 vcpkg_extract_source_archive(
@@ -15,6 +15,7 @@ vcpkg_extract_source_archive(
     ARCHIVE "${LIBRESSL_SOURCE_ARCHIVE}"
     PATCHES
         pkgconfig.diff
+        aarch64-windows.diff
 )
 
 vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
diff --git a/ports/libressl/vcpkg.json b/ports/libressl/vcpkg.json
index 443bd8f93f..79e6c835a1 100644
--- a/ports/libressl/vcpkg.json
+++ b/ports/libressl/vcpkg.json
@@ -1,6 +1,6 @@
 {
   "name": "libressl",
-  "version": "4.1.1",
+  "version": "4.2.0",
   "description": [
     "LibreSSL is a TLS/crypto stack.",
     "It was forked from OpenSSL in 2014 by the OpenBSD project, with goals of modernizing the codebase, improving security, and applying best practice development processes.",
diff --git a/versions/baseline.json b/versions/baseline.json
index 8e9ea18354..0059983184 100644
--- a/versions/baseline.json
+++ b/versions/baseline.json
@@ -5361,7 +5361,7 @@
       "port-version": 2
     },
     "libressl": {
-      "baseline": "4.1.1",
+      "baseline": "4.2.0",
       "port-version": 0
     },
     "librsvg": {
diff --git a/versions/l-/libressl.json b/versions/l-/libressl.json
index c47a745280..a175ad2bc7 100644
--- a/versions/l-/libressl.json
+++ b/versions/l-/libressl.json
@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "29d9b59ae2e3ab8f916d806eccf19f26253312ce",
+      "version": "4.2.0",
+      "port-version": 0
+    },
     {
       "git-tree": "bc7b120ae250132a5180932927dbee09de661675",
       "version": "4.1.1",