--- /dev/null
+From b4d87554cf82db109b21e905fb57df05df8adbdc Mon Sep 17 00:00:00 2001
+From: Julien Schueller <schueller@phimeca.com>
+Date: Mon, 19 Jan 2026 14:49:34 +0100
+Subject: [PATCH] CMake: Fix EXPAT version warning
+
+Closes #19679
+---
+ CMake/FindEXPAT.cmake | 11 ++++++-----
+ ThirdParty/expat/CMakeLists.txt | 7 ++++---
+ 2 files changed, 10 insertions(+), 8 deletions(-)
+
+diff --git a/CMake/FindEXPAT.cmake b/CMake/FindEXPAT.cmake
+index 00b160a4952..5dda968d005 100644
+--- a/CMake/FindEXPAT.cmake
++++ b/CMake/FindEXPAT.cmake
+@@ -43,25 +43,26 @@ if (EXPAT_INCLUDE_DIR AND EXISTS "${EXPAT_INCLUDE_DIR}/expat.h")
+ file(STRINGS "${EXPAT_INCLUDE_DIR}/expat.h" expat_version_str
+ REGEX "^#[\t ]*define[\t ]+XML_(MAJOR|MINOR|MICRO)_VERSION[\t ]+[0-9]+$")
+
+- unset(EXPAT_VERSION_STRING)
++ unset(EXPAT_VERSION)
+ foreach(VPART MAJOR MINOR MICRO)
+ foreach(VLINE ${expat_version_str})
+ if(VLINE MATCHES "^#[\t ]*define[\t ]+XML_${VPART}_VERSION[\t ]+([0-9]+)$")
+ set(EXPAT_VERSION_PART "${CMAKE_MATCH_1}")
+- if(EXPAT_VERSION_STRING)
+- string(APPEND EXPAT_VERSION_STRING ".${EXPAT_VERSION_PART}")
++ if(EXPAT_VERSION)
++ string(APPEND EXPAT_VERSION ".${EXPAT_VERSION_PART}")
+ else()
+- set(EXPAT_VERSION_STRING "${EXPAT_VERSION_PART}")
++ set(EXPAT_VERSION "${EXPAT_VERSION_PART}")
+ endif()
+ endif()
+ endforeach()
+ endforeach()
++ set(EXPAT_VERSION_STRING ${EXPAT_VERSION})
+ endif ()
+
+ include(FindPackageHandleStandardArgs)
+ FIND_PACKAGE_HANDLE_STANDARD_ARGS(EXPAT
+ REQUIRED_VARS EXPAT_LIBRARY EXPAT_INCLUDE_DIR
+- VERSION_VAR EXPAT_VERSION_STRING)
++ VERSION_VAR EXPAT_VERSION)
+
+ # Copy the results to the output variables and target.
+ if(EXPAT_FOUND)
+diff --git a/ThirdParty/expat/CMakeLists.txt b/ThirdParty/expat/CMakeLists.txt
+index a08980c8442..90e3ce28eff 100644
+--- a/ThirdParty/expat/CMakeLists.txt
++++ b/ThirdParty/expat/CMakeLists.txt
+@@ -16,7 +16,8 @@ vtk_module_third_party(
+ PACKAGE EXPAT
+ VERSION 2.2.1 # absolute minimun, correspending to version in macOS 10.13
+ TARGETS EXPAT::EXPAT
+- STANDARD_INCLUDE_DIRS)
++ STANDARD_INCLUDE_DIRS
++ USE_VARIABLES EXPAT_VERSION)
+
+ include(vtkDetectLibraryType)
+ vtk_detect_library_shared(vtkexpat EXPAT::EXPAT)
+@@ -42,9 +43,9 @@ vtk_module_install_headers(
+ if(NOT DEFINED ENV{DASHBOARD_TEST_FROM_CTEST})
+ # Check for deprecated versions of expat
+ set(expat_deprecated_version "2.6.3")
+- if(VTK_MODULE_USE_EXTERNAL_vtkexpat AND EXPAT_VERSION_STRING VERSION_LESS expat_deprecated_version)
++ if(VTK_MODULE_USE_EXTERNAL_vtkexpat AND EXPAT_VERSION VERSION_LESS expat_deprecated_version)
+ message(DEPRECATION
+- "External expat ${EXPAT_VERSION_STRING} is less than ${expat_deprecated_version} "
++ "External expat ${EXPAT_VERSION} is less than ${expat_deprecated_version} "
+ "and (may) have known vulnerabilities. Consider upgrading.")
+ endif()
+ endif()
+--
+GitLab
+