diff --git a/Help/manual/cmake-file-api.7.rst b/Help/manual/cmake-file-api.7.rst
index 5f16a8b47..88a7bab96 100644
--- a/Help/manual/cmake-file-api.7.rst
+++ b/Help/manual/cmake-file-api.7.rst
@@ -1093,8 +1093,10 @@ with members:
     ``PRIVATE``, or ``INTERFACE``.
 
   ``baseDirectories``
-    A JSON array of strings specifying the base directories containing sources
-    in the file set.
+    A JSON array of strings, each specifying a base directory containing
+    sources in the file set.  If the directory is inside the top-level source
+    directory then the path is specified relative to that directory.
+    Otherwise the path is absolute.
 
   This field was added in codemodel version 2.5.
 
diff --git a/Help/manual/ctest.1.rst b/Help/manual/ctest.1.rst
index 5c3889e3b..40a332d07 100644
--- a/Help/manual/ctest.1.rst
+++ b/Help/manual/ctest.1.rst
@@ -652,6 +652,8 @@ a `CDash`_ server. The command-line signature used to submit to `CDash`_ is::
   ctest -S <script>            [-- <dashboard-options>...]
   ctest -SP <script>           [-- <dashboard-options>...]
 
+.. _`CDash`: https://www.cdash.org
+
 Options for Dashboard Client include:
 
 .. option:: -D <dashboard>, --dashboard <dashboard>
@@ -1822,5 +1824,3 @@ See Also
 ========
 
 .. include:: LINKS.txt
-
-_`CDash`: https://cdash.org
diff --git a/Help/policy/CMP0149.rst b/Help/policy/CMP0149.rst
index 714eeaff2..a84149f82 100644
--- a/Help/policy/CMP0149.rst
+++ b/Help/policy/CMP0149.rst
@@ -35,6 +35,13 @@ This policy provides compatibility for projects, toolchain files, and
 build scripts that have not been ported away from using
 :variable:`CMAKE_SYSTEM_VERSION` to specify an exact SDK version.
 
+.. note::
+
+  This policy must be set before the first :command:`project` or
+  :command:`enable_language` command invocation at the top of the
+  project.  That is when :ref:`Visual Studio Generators` select a
+  Windows SDK.
+
 The ``OLD`` behavior for this policy is to use the exact value of
 :variable:`CMAKE_SYSTEM_VERSION` if possible.  The ``NEW`` behavior
 for this policy is to ignore it.
diff --git a/Help/release/3.26.rst b/Help/release/3.26.rst
index c73c59abf..72ffad8cf 100644
--- a/Help/release/3.26.rst
+++ b/Help/release/3.26.rst
@@ -181,3 +181,13 @@ Changes made since CMake 3.26.0 include the following.
 * These versions made no changes to documented features or interfaces.
   Some implementation updates were made to support ecosystem changes
   and/or fix regressions.
+
+3.26.6
+------
+
+* The :manual:`cmake-file-api(7)` "codemodel" version 2 "target" object
+  ``fileSets`` field was introduced by CMake 3.26.0 with entries of its
+  ``baseDirectories`` member incorrectly expressed as absolute paths
+  even if they are inside the top-level source directory.  This has
+  been fixed.  Clients must be updated to expect relative paths under
+  the top-level source directory.
diff --git a/Help/release/3.27.rst b/Help/release/3.27.rst
index 8a67ebc2e..4d90d14bb 100644
--- a/Help/release/3.27.rst
+++ b/Help/release/3.27.rst
@@ -291,3 +291,23 @@ Changes made since CMake 3.27.0 include the following.
 * These versions made no changes to documented features or interfaces.
   Some implementation updates were made to support ecosystem changes
   and/or fix regressions.
+
+3.27.9
+------
+
+* The :manual:`cmake-file-api(7)` "codemodel" version 2 "target" object
+  ``fileSets`` field was introduced by CMake 3.26.0 with entries of its
+  ``baseDirectories`` member incorrectly expressed as absolute paths
+  even if they are inside the top-level source directory.  This was
+  fixed in CMake 3.26.6 and has now been fixed in 3.27.9.  Clients must
+  be updated to expect relative paths under the top-level source directory.
+
+* Fortran module dependency scanning in :ref:`Ninja Generators` was updated
+  by CMake 3.27.0 to use exact collation dependencies.  This was supposed
+  to fix subtle rebuild failures when moving module sources among targets.
+  Since then, several cases have been found in which exact collation
+  dependencies were incorrectly computed when using :ref:`Object Libraries`.
+  Some of these cases were incrementally fixed through the 3.27.x patch
+  series, but additional more subtle cases have since been found.  In order
+  to avoid further churn in the 3.27 release series, the original change has
+  been reverted and deferred to a future version of CMake.
diff --git a/Source/CMakeVersion.cmake b/Source/CMakeVersion.cmake
index 8af86f55d..acf1e0cc8 100644
--- a/Source/CMakeVersion.cmake
+++ b/Source/CMakeVersion.cmake
@@ -1,7 +1,7 @@
 # CMake version number components.
 set(CMake_VERSION_MAJOR 3)
 set(CMake_VERSION_MINOR 27)
-set(CMake_VERSION_PATCH 8)
+set(CMake_VERSION_PATCH 9)
 #set(CMake_VERSION_RC 0)
 set(CMake_VERSION_IS_DIRTY 0)
 
@@ -21,7 +21,7 @@ endif()
 
 if(NOT CMake_VERSION_NO_GIT)
   # If this source was exported by 'git archive', use its commit info.
-  set(git_info [==[9cfff766eb CMake 3.27.8]==])
+  set(git_info [==[c4f7eb3f0b CMake 3.27.9]==])
 
   # Otherwise, try to identify the current development source version.
   if(NOT git_info MATCHES "^([0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]?[0-9a-f]?)[0-9a-f]* "
diff --git a/Source/cmFileAPICodemodel.cxx b/Source/cmFileAPICodemodel.cxx
index 280ebb013..53efb0deb 100644
--- a/Source/cmFileAPICodemodel.cxx
+++ b/Source/cmFileAPICodemodel.cxx
@@ -1636,7 +1636,7 @@ Json::Value Target::DumpFileSet(cmFileSet const* fs,
 
   Json::Value baseDirs = Json::arrayValue;
   for (auto const& directory : directories) {
-    baseDirs.append(directory);
+    baseDirs.append(RelativeIfUnder(this->TopSource, directory));
   }
   fileSet["baseDirectories"] = baseDirs;
 
diff --git a/Source/cmGccDepfileLexerHelper.cxx b/Source/cmGccDepfileLexerHelper.cxx
index 87377de40..ae8892a46 100644
--- a/Source/cmGccDepfileLexerHelper.cxx
+++ b/Source/cmGccDepfileLexerHelper.cxx
@@ -145,8 +145,8 @@ void cmGccDepfileLexerHelper::sanitizeContent()
         ++rit;
       }
     }
-    // Remove the entry if rules are empty or do not have any paths
-    if (it->rules.empty() || it->paths.empty()) {
+    // Remove the entry if rules are empty
+    if (it->rules.empty()) {
       it = this->Content.erase(it);
     } else {
       ++it;
diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index d712d7195..bc04d1fee 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -1034,11 +1034,6 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatements(
 
     cmNinjaBuild build(this->LanguageDyndepRule(language, config));
     build.Outputs.push_back(this->GetDyndepFilePath(language, config));
-    build.ImplicitOuts.push_back(
-      cmStrCat(this->Makefile->GetCurrentBinaryDirectory(), '/',
-               this->LocalGenerator->GetTargetDirectory(this->GeneratorTarget),
-               this->GetGlobalGenerator()->ConfigDirectory(config), '/',
-               language, "Modules.json"));
     for (auto const& scanFiles : scanningFiles) {
       if (!scanFiles.ScanningOutput.empty()) {
         build.ExplicitDeps.push_back(scanFiles.ScanningOutput);
@@ -1050,10 +1045,17 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatements(
 
     this->WriteTargetDependInfo(language, config);
 
-    for (std::string const& l :
-         this->GetLinkedTargetDirectories(language, config)) {
-      build.ImplicitDeps.push_back(cmStrCat(l, '/', language, "Modules.json"));
-    }
+    // Make sure dyndep files for all our dependencies have already
+    // been generated so that the '<LANG>Modules.json' files they
+    // produced as side-effects are available for us to read.
+    // Ideally we should depend on the '<LANG>Modules.json' files
+    // from our dependencies directly, but we don't know which of
+    // our dependencies produces them.  Fixing this will require
+    // refactoring the Ninja generator to generate targets in
+    // dependency order so that we can collect the needed information.
+    this->GetLocalGenerator()->AppendTargetDepends(
+      this->GeneratorTarget, build.OrderOnlyDeps, config, fileConfig,
+      DependOnTargetArtifact);
 
     this->GetGlobalGenerator()->WriteBuild(this->GetImplFileStream(fileConfig),
                                            build);
diff --git a/Tests/FortranModules/CMakeLists.txt b/Tests/FortranModules/CMakeLists.txt
index 16ea0d4da..1e5ff89ec 100644
--- a/Tests/FortranModules/CMakeLists.txt
+++ b/Tests/FortranModules/CMakeLists.txt
@@ -137,3 +137,9 @@ add_subdirectory(Issue25252-iface-sources)
 
 add_subdirectory(Issue25365-target-objects)
 add_subdirectory(Issue25365-target-objects-iface)
+
+# Issue#25425
+add_subdirectory(ModulesViaTargetObjectsSource)
+add_subdirectory(ModulesViaSubdirTargetObjectsSource)
+add_subdirectory(ModulesViaTargetObjectsLink)
+add_subdirectory(ModulesViaSubdirTargetObjectsLink)
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/CMakeLists.txt b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/CMakeLists.txt
new file mode 100644
index 000000000..b52b423fe
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/CMakeLists.txt
@@ -0,0 +1,7 @@
+add_subdirectory(subdir)
+
+add_library(mvstol_lib dummy.f90)
+target_link_libraries(mvstol_lib PRIVATE "$<TARGET_OBJECTS:mvstol_obj>")
+target_include_directories(mvstol_lib PUBLIC "${CMAKE_CURRENT_BINARY_DIR}/subdir")
+add_library(mvstol_use use.f90)
+target_link_libraries(mvstol_use PRIVATE mvstol_lib)
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/dummy.f90 b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/dummy.f90
new file mode 100644
index 000000000..96a813809
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/dummy.f90
@@ -0,0 +1,3 @@
+pure real function dummy()
+dummy = 4*atan(1.)
+end function
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/subdir/CMakeLists.txt b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/subdir/CMakeLists.txt
new file mode 100644
index 000000000..b2a250d21
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/subdir/CMakeLists.txt
@@ -0,0 +1 @@
+add_library(mvstol_obj STATIC obj.f90)
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/subdir/obj.f90 b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/subdir/obj.f90
new file mode 100644
index 000000000..6b5ddd59f
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/subdir/obj.f90
@@ -0,0 +1,11 @@
+module m1
+
+implicit none
+
+contains
+
+pure real function pi()
+pi = 4*atan(1.)
+end function
+
+end module m1
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/use.f90 b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/use.f90
new file mode 100644
index 000000000..f97190970
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsLink/use.f90
@@ -0,0 +1,13 @@
+module lib
+
+use m1, only : pi
+
+implicit none
+
+contains
+
+pure real function func()
+func = pi()
+end function
+
+end module
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/CMakeLists.txt b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/CMakeLists.txt
new file mode 100644
index 000000000..255e8a72e
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_subdirectory(subdir)
+
+add_library(mvstos_lib "$<TARGET_OBJECTS:mvstos_obj>")
+target_include_directories(mvstos_lib PUBLIC "${CMAKE_CURRENT_BINARY_DIR}/subdir")
+add_library(mvstos_use use.f90)
+target_link_libraries(mvstos_use PRIVATE mvstos_lib)
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/subdir/CMakeLists.txt b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/subdir/CMakeLists.txt
new file mode 100644
index 000000000..acc0da91f
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/subdir/CMakeLists.txt
@@ -0,0 +1 @@
+add_library(mvstos_obj OBJECT obj.f90)
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/subdir/obj.f90 b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/subdir/obj.f90
new file mode 100644
index 000000000..6b5ddd59f
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/subdir/obj.f90
@@ -0,0 +1,11 @@
+module m1
+
+implicit none
+
+contains
+
+pure real function pi()
+pi = 4*atan(1.)
+end function
+
+end module m1
diff --git a/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/use.f90 b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/use.f90
new file mode 100644
index 000000000..f97190970
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaSubdirTargetObjectsSource/use.f90
@@ -0,0 +1,13 @@
+module lib
+
+use m1, only : pi
+
+implicit none
+
+contains
+
+pure real function func()
+func = pi()
+end function
+
+end module
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsLink/CMakeLists.txt b/Tests/FortranModules/ModulesViaTargetObjectsLink/CMakeLists.txt
new file mode 100644
index 000000000..202e59ed1
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsLink/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_library(mvtol_obj STATIC obj.f90)
+add_library(mvtol_lib dummy.f90)
+target_link_libraries(mvtol_lib PRIVATE "$<TARGET_OBJECTS:mvtol_obj>")
+add_library(mvtol_use use.f90)
+target_link_libraries(mvtol_use PRIVATE mvtol_lib)
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsLink/dummy.f90 b/Tests/FortranModules/ModulesViaTargetObjectsLink/dummy.f90
new file mode 100644
index 000000000..96a813809
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsLink/dummy.f90
@@ -0,0 +1,3 @@
+pure real function dummy()
+dummy = 4*atan(1.)
+end function
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsLink/obj.f90 b/Tests/FortranModules/ModulesViaTargetObjectsLink/obj.f90
new file mode 100644
index 000000000..6b5ddd59f
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsLink/obj.f90
@@ -0,0 +1,11 @@
+module m1
+
+implicit none
+
+contains
+
+pure real function pi()
+pi = 4*atan(1.)
+end function
+
+end module m1
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsLink/use.f90 b/Tests/FortranModules/ModulesViaTargetObjectsLink/use.f90
new file mode 100644
index 000000000..f97190970
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsLink/use.f90
@@ -0,0 +1,13 @@
+module lib
+
+use m1, only : pi
+
+implicit none
+
+contains
+
+pure real function func()
+func = pi()
+end function
+
+end module
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsSource/CMakeLists.txt b/Tests/FortranModules/ModulesViaTargetObjectsSource/CMakeLists.txt
new file mode 100644
index 000000000..9113a11e6
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsSource/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_library(mvtos_obj OBJECT obj.f90)
+add_library(mvtos_lib "$<TARGET_OBJECTS:mvtos_obj>")
+add_library(mvtos_use use.f90)
+target_link_libraries(mvtos_use PRIVATE mvtos_lib)
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsSource/obj.f90 b/Tests/FortranModules/ModulesViaTargetObjectsSource/obj.f90
new file mode 100644
index 000000000..6b5ddd59f
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsSource/obj.f90
@@ -0,0 +1,11 @@
+module m1
+
+implicit none
+
+contains
+
+pure real function pi()
+pi = 4*atan(1.)
+end function
+
+end module m1
diff --git a/Tests/FortranModules/ModulesViaTargetObjectsSource/use.f90 b/Tests/FortranModules/ModulesViaTargetObjectsSource/use.f90
new file mode 100644
index 000000000..f97190970
--- /dev/null
+++ b/Tests/FortranModules/ModulesViaTargetObjectsSource/use.f90
@@ -0,0 +1,13 @@
+module lib
+
+use m1, only : pi
+
+implicit none
+
+contains
+
+pure real function func()
+func = pi()
+end function
+
+end module
diff --git a/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_1.json b/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_1.json
index f6cfa9c75..8d1d21901 100644
--- a/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_1.json
+++ b/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_1.json
@@ -10,25 +10,25 @@
       "name": "HEADERS",
       "type": "HEADERS",
       "visibility": "PUBLIC",
-      "baseDirectories": [".*/Tests/RunCMake/FileAPI/fileset$"]
+      "baseDirectories": ["^fileset$"]
     },
     {
       "name": "a",
       "type": "HEADERS",
       "visibility": "PRIVATE",
-      "baseDirectories": [".*/Tests/RunCMake/FileAPI/fileset$"]
+      "baseDirectories": ["^fileset$"]
     },
     {
       "name": "b",
       "type": "HEADERS",
       "visibility": "PUBLIC",
-      "baseDirectories": [".*/Tests/RunCMake/FileAPI/fileset/dir$"]
+      "baseDirectories": ["^fileset/dir$"]
     },
     {
       "name": "c",
       "type": "HEADERS",
       "visibility": "INTERFACE",
-      "baseDirectories": [".*/Tests/RunCMake/FileAPI/fileset$"]
+      "baseDirectories": ["^fileset$"]
     }
   ],
   "sources": [
diff --git a/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_2.json b/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_2.json
index 591ba4f8e..e97f6d49b 100644
--- a/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_2.json
+++ b/Tests/RunCMake/FileAPI/codemodel-v2-data/targets/c_headers_2.json
@@ -10,7 +10,7 @@
       "name": "HEADERS",
       "type": "HEADERS",
       "visibility": "INTERFACE",
-      "baseDirectories": [".*/Tests/RunCMake/FileAPI/fileset$"]
+      "baseDirectories": ["^fileset$"]
     }
   ],
   "sources": [