diff --git a/Misc/NEWS.d/next/Windows/2025-11-04-19-20-05.gh-issue-140849.YjB2ZZ.rst b/Misc/NEWS.d/next/Windows/2025-11-04-19-20-05.gh-issue-140849.YjB2ZZ.rst
new file mode 100644
index 00000000000000..6f25b8675663fd
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2025-11-04-19-20-05.gh-issue-140849.YjB2ZZ.rst
@@ -0,0 +1 @@
+Update bundled liblzma to version 5.8.1.
diff --git a/Misc/externals.spdx.json b/Misc/externals.spdx.json
index 59aceedb94d4c7..dba01de8352d52 100644
--- a/Misc/externals.spdx.json
+++ b/Misc/externals.spdx.json
@@ -154,21 +154,21 @@
       "checksums": [
         {
           "algorithm": "SHA256",
-          "checksumValue": "a15c168e39e87d750c3dc766edc7f19bdda57dacf01e509678467eace91ad282"
+          "checksumValue": "1bfaba0ccacc6681d3ba85335cc7f49c24cf6f9d16f848cbd153b896d8a7d631"
         }
       ],
-      "downloadLocation": "https://github.com/python/cpython-source-deps/archive/refs/tags/xz-5.2.5.tar.gz",
+      "downloadLocation": "https://github.com/python/cpython-source-deps/archive/refs/tags/xz-5.8.1.1.tar.gz",
       "externalRefs": [
         {
           "referenceCategory": "SECURITY",
-          "referenceLocator": "cpe:2.3:a:tukaani:xz:5.2.5:*:*:*:*:*:*:*",
+          "referenceLocator": "cpe:2.3:a:tukaani:xz:5.8.1.1:*:*:*:*:*:*:*",
           "referenceType": "cpe23Type"
         }
       ],
       "licenseConcluded": "NOASSERTION",
       "name": "xz",
       "primaryPackagePurpose": "SOURCE",
-      "versionInfo": "5.2.5"
+      "versionInfo": "5.8.1.1"
     },
     {
       "SPDXID": "SPDXRef-PACKAGE-zlib-ng",
diff --git a/PCbuild/get_externals.bat b/PCbuild/get_externals.bat
index 319024e0f50f46..115203cecc8e48 100644
--- a/PCbuild/get_externals.bat
+++ b/PCbuild/get_externals.bat
@@ -59,7 +59,7 @@ set libraries=%libraries%                                       mpdecimal-4.0.0
 set libraries=%libraries%                                       sqlite-3.50.4.0
 if NOT "%IncludeTkinterSrc%"=="false" set libraries=%libraries% tcl-core-8.6.15.0
 if NOT "%IncludeTkinterSrc%"=="false" set libraries=%libraries% tk-8.6.15.0
-set libraries=%libraries%                                       xz-5.2.5
+set libraries=%libraries%                                       xz-5.8.1.1
 set libraries=%libraries%                                       zlib-ng-2.2.4
 set libraries=%libraries%                                       zstd-1.5.7
 
diff --git a/PCbuild/liblzma.vcxproj b/PCbuild/liblzma.vcxproj
index 97938692328495..75d4e16234618e 100644
--- a/PCbuild/liblzma.vcxproj
+++ b/PCbuild/liblzma.vcxproj
@@ -92,7 +92,7 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <PreprocessorDefinitions>WIN32;HAVE_CONFIG_H;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <AdditionalIncludeDirectories>$(lzmaDir)windows/vs2019;$(lzmaDir)src/liblzma/common;$(lzmaDir)src/common;$(lzmaDir)src/liblzma/api;$(lzmaDir)src/liblzma/check;$(lzmaDir)src/liblzma/delta;$(lzmaDir)src/liblzma/lz;$(lzmaDir)src/liblzma/lzma;$(lzmaDir)src/liblzma/rangecoder;$(lzmaDir)src/liblzma/simple;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(lzmaDir)windows;$(lzmaDir)src/liblzma/common;$(lzmaDir)src/common;$(lzmaDir)src/liblzma/api;$(lzmaDir)src/liblzma/check;$(lzmaDir)src/liblzma/delta;$(lzmaDir)src/liblzma/lz;$(lzmaDir)src/liblzma/lzma;$(lzmaDir)src/liblzma/rangecoder;$(lzmaDir)src/liblzma/simple;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <DisableSpecificWarnings>4244;4267;4996;%(DisableSpecificWarnings)</DisableSpecificWarnings>
       <AdditionalOptions Condition="$(PlatformToolset) == 'ClangCL'">%(AdditionalOptions) -Wno-deprecated-declarations</AdditionalOptions>
     </ClCompile>
@@ -102,9 +102,7 @@
     <ClCompile Include="$(lzmaDir)src\common\tuklib_physmem.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\check\check.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\check\crc32_fast.c" />
-    <ClCompile Include="$(lzmaDir)src\liblzma\check\crc32_table.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\check\crc64_fast.c" />
-    <ClCompile Include="$(lzmaDir)src\liblzma\check\crc64_table.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\check\sha256.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\common\alone_decoder.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\common\alone_encoder.c" />
@@ -163,6 +161,7 @@
     <ClCompile Include="$(lzmaDir)src\liblzma\lz\lz_encoder_mf.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\rangecoder\price_table.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\simple\arm.c" />
+    <ClCompile Include="$(lzmaDir)src\liblzma\simple\arm64.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\simple\armthumb.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\simple\ia64.c" />
     <ClCompile Include="$(lzmaDir)src\liblzma\simple\powerpc.c" />
@@ -239,7 +238,7 @@
     <ClInclude Include="$(lzmaDir)src\liblzma\simple\simple_decoder.h" />
     <ClInclude Include="$(lzmaDir)src\liblzma\simple\simple_encoder.h" />
     <ClInclude Include="$(lzmaDir)src\liblzma\simple\simple_private.h" />
-    <ClInclude Include="$(lzmaDir)windows\vs2019\config.h" />
+    <ClInclude Include="$(lzmaDir)windows\config.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
diff --git a/PCbuild/liblzma.vcxproj.filters b/PCbuild/liblzma.vcxproj.filters
index ebe2a7d5fa9e5d..42feca5a3414bf 100644
--- a/PCbuild/liblzma.vcxproj.filters
+++ b/PCbuild/liblzma.vcxproj.filters
@@ -18,6 +18,9 @@
     <ClCompile Include="$(lzmaDir)src\liblzma\simple\arm.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="$(lzmaDir)src\liblzma\simple\arm64.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="$(lzmaDir)src\liblzma\simple\armthumb.c">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -54,15 +57,9 @@
     <ClCompile Include="$(lzmaDir)src\liblzma\check\crc32_fast.c">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="$(lzmaDir)src\liblzma\check\crc32_table.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="$(lzmaDir)src\liblzma\check\crc64_fast.c">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="$(lzmaDir)src\liblzma\check\crc64_table.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="$(lzmaDir)src\liblzma\delta\delta_common.c">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -428,7 +425,7 @@
     <ClInclude Include="$(lzmaDir)src\liblzma\simple\simple_private.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="$(lzmaDir)windows\vs2019\config.h">
+    <ClInclude Include="$(lzmaDir)windows\config.h">
       <Filter>Header Files</Filter>
     </ClInclude>
   </ItemGroup>
diff --git a/PCbuild/python.props b/PCbuild/python.props
index cc1572526559ce..7840e2a1cfc8e2 100644
--- a/PCbuild/python.props
+++ b/PCbuild/python.props
@@ -77,7 +77,7 @@
   <PropertyGroup>
     <sqlite3Dir Condition="$(sqlite3Dir) == ''">$(ExternalsDir)sqlite-3.50.4.0\</sqlite3Dir>
     <bz2Dir Condition="$(bz2Dir) == ''">$(ExternalsDir)bzip2-1.0.8\</bz2Dir>
-    <lzmaDir Condition="$(lzmaDir) == ''">$(ExternalsDir)xz-5.2.5\</lzmaDir>
+    <lzmaDir Condition="$(lzmaDir) == ''">$(ExternalsDir)xz-5.8.1.1\</lzmaDir>
     <libffiDir Condition="$(libffiDir) == ''">$(ExternalsDir)libffi-3.4.4\</libffiDir>
     <libffiOutDir Condition="$(libffiOutDir) == ''">$(libffiDir)$(ArchName)\</libffiOutDir>
     <libffiIncludeDir Condition="$(libffiIncludeDir) == ''">$(libffiOutDir)include</libffiIncludeDir>