diff --git a/ci/build.linux.gitlab-ci.yml b/ci/build.linux.gitlab-ci.yml
index cf02b2b73..ab018c089 100644
--- a/ci/build.linux.gitlab-ci.yml
+++ b/ci/build.linux.gitlab-ci.yml
@@ -51,45 +51,28 @@ build:linux:cross:x86-64:gcc-10:avx512dq:
   variables:
     EIGEN_CI_ADDITIONAL_ARGS: "-DEIGEN_TEST_AVX512DQ=on"
 
-# Clang-6 (minimum on Ubuntu 20.04)
-build:linux:cross:x86-64:clang-6:default:
-  extends: .build:linux:cross:x86-64
-  image: ubuntu:20.04
-  variables:
-    EIGEN_CI_INSTALL: g++-8 clang-6.0 lld-6.0
-    EIGEN_CI_C_COMPILER: clang-6.0
-    EIGEN_CI_CXX_COMPILER: clang++-6.0
-    EIGEN_CI_CROSS_INSTALL: g++-8-x86-64-linux-gnu clang-6.0 lld-6.0
-    EIGEN_CI_ADDITIONAL_ARGS: -DCMAKE_EXE_LINKER_FLAGS=-fuse-ld=lld-6.0
-
-# Clang-12 (stable recent version)
-build:linux:cross:x86-64:clang-12:default:
+# Clang-14 (stable recent version)
+build:linux:cross:x86-64:clang-14:default:
   extends: .build:linux:cross:x86-64
   variables:
-    EIGEN_CI_INSTALL: clang-12
-    EIGEN_CI_C_COMPILER: clang-12
-    EIGEN_CI_CXX_COMPILER: clang++-12
-    EIGEN_CI_CROSS_INSTALL: g++-10-x86-64-linux-gnu clang-12
+    EIGEN_CI_INSTALL: clang-14
+    EIGEN_CI_C_COMPILER: clang-14
+    EIGEN_CI_CXX_COMPILER: clang++-14
+    EIGEN_CI_CROSS_INSTALL: g++-10-x86-64-linux-gnu clang-14
 
-build:linux:cross:x86-64:clang-12:avx:
-  extends: build:linux:cross:x86-64:clang-12:default
-  variables:
-    EIGEN_CI_ADDITIONAL_ARGS: "-DEIGEN_TEST_AVX=on"
-
-build:linux:cross:x86-64:clang-12:avx2:
-  extends: build:linux:cross:x86-64:clang-12:default
+build:linux:cross:x86-64:clang-14:avx2:
+  extends: build:linux:cross:x86-64:clang-14:default
   variables:
     EIGEN_CI_ADDITIONAL_ARGS: "-DEIGEN_TEST_AVX2=on"
 
-build:linux:cross:x86-64:clang-12:avx512dq:
-  extends: build:linux:cross:x86-64:clang-12:default
+build:linux:cross:x86-64:clang-14:avx512dq:
+  extends: build:linux:cross:x86-64:clang-14:default
   variables:
     EIGEN_CI_ADDITIONAL_ARGS: "-DEIGEN_TEST_AVX512DQ=on"
 
 # Generic vector extension backend.
 build:linux:cross:x86-64:clang-19:generic:avx512dq:
-  image: ubuntu:24.04
-  extends: build:linux:cross:x86-64:clang-12:default
+  extends: build:linux:cross:x86-64:clang-14:default
   variables:
     EIGEN_CI_INSTALL: clang-19
     EIGEN_CI_C_COMPILER: clang-19
@@ -101,7 +84,6 @@ build:linux:cross:x86-64:clang-19:generic:avx512dq:
 # Nightly full test suite in C++20 mode.
 build:linux:cross:x86-64:clang-19:cxx20:nightly:
   extends: .build:linux:cross:x86-64
-  image: ubuntu:24.04
   variables:
     EIGEN_CI_INSTALL: clang-19
     EIGEN_CI_C_COMPILER: clang-19
@@ -135,7 +117,6 @@ build:linux:docs:
 # instrumented executables are too large to upload as a single artifact.
 .build:linux:cross:x86-64:clang-19:default:asan-ubsan:
   extends: .build:linux:cross:x86-64
-  image: ubuntu:24.04
   # Disable cache for ASAN builds: instrumented .o files are so large that
   # downloading the cache can take longer than a clean build from scratch.
   cache: []
@@ -249,13 +230,13 @@ build:linux:cross:arm:gcc-10:default:
     EIGEN_CI_CROSS_C_COMPILER: arm-linux-gnueabihf-gcc-10
     EIGEN_CI_CROSS_CXX_COMPILER: arm-linux-gnueabihf-g++-10
 
-build:linux:cross:arm:clang-12:default:
+build:linux:cross:arm:clang-14:default:
   extends: .build:linux:cross:arm
   variables:
-    EIGEN_CI_INSTALL: clang-12
-    EIGEN_CI_C_COMPILER: clang-12
-    EIGEN_CI_CXX_COMPILER: clang++-12
-    EIGEN_CI_CROSS_INSTALL: g++-10-arm-linux-gnueabihf clang-12 qemu-user-static
+    EIGEN_CI_INSTALL: clang-14
+    EIGEN_CI_C_COMPILER: clang-14
+    EIGEN_CI_CXX_COMPILER: clang++-14
+    EIGEN_CI_CROSS_INSTALL: g++-10-arm-linux-gnueabihf clang-14 qemu-user-static
 
 ######## aarch64 ###############################################################
 
@@ -277,19 +258,18 @@ build:linux:cross:aarch64:gcc-10:default:
     EIGEN_CI_CROSS_C_COMPILER: aarch64-linux-gnu-gcc-10
     EIGEN_CI_CROSS_CXX_COMPILER: aarch64-linux-gnu-g++-10
 
-build:linux:cross:aarch64:clang-12:default:
+build:linux:cross:aarch64:clang-14:default:
   extends: .build:linux:cross:aarch64
   variables:
-    EIGEN_CI_INSTALL: clang-12
-    EIGEN_CI_C_COMPILER: clang-12
-    EIGEN_CI_CXX_COMPILER: clang++-12
-    EIGEN_CI_CROSS_INSTALL: g++-10-aarch64-linux-gnu clang-12
+    EIGEN_CI_INSTALL: clang-14
+    EIGEN_CI_C_COMPILER: clang-14
+    EIGEN_CI_CXX_COMPILER: clang++-14
+    EIGEN_CI_CROSS_INSTALL: g++-10-aarch64-linux-gnu clang-14
 
 ######## ppc64le ###############################################################
 
 .build:linux:cross:ppc64le:
   extends: .build:linux:cross
-  image: ubuntu:24.04
   variables:
     EIGEN_CI_TARGET_ARCH: ppc64le
     EIGEN_CI_CROSS_TARGET_TRIPLE: powerpc64le-linux-gnu
@@ -322,7 +302,6 @@ build:linux:cross:ppc64le:clang-16:default:
 # GCC-14 (minimum on Ubuntu 24)
 build:linux:cross:loongarch64:gcc-14:default:
   extends: .build:linux:cross:loongarch64
-  image: ubuntu:24.04
   variables:
     EIGEN_CI_CROSS_INSTALL: g++-14-loongarch64-linux-gnu qemu-user-static
     EIGEN_CI_CROSS_C_COMPILER: loongarch64-linux-gnu-gcc-14
@@ -343,8 +322,8 @@ build:linux:cross:x86-64:gcc-10:default:smoketest:
   tags:
     - saas-linux-medium-amd64
 
-build:linux:cross:x86-64:clang-12:default:smoketest:
-  extends: build:linux:cross:x86-64:clang-12:default
+build:linux:cross:x86-64:clang-14:default:smoketest:
+  extends: build:linux:cross:x86-64:clang-14:default
   variables:
     EIGEN_CI_BUILD_TARGET: buildsmoketests
   rules:
@@ -363,8 +342,8 @@ build:linux:aarch64:gcc-10:default:smoketest:
 
 ######## Sanitizer Smoke Tests #################################################
 
-build:linux:cross:x86-64:clang-12:sanitizer:smoketest:
-  extends: build:linux:cross:x86-64:clang-12:default
+build:linux:cross:x86-64:clang-14:sanitizer:smoketest:
+  extends: build:linux:cross:x86-64:clang-14:default
   variables:
     EIGEN_CI_BUILD_TARGET: buildsmoketests
     EIGEN_CI_ADDITIONAL_ARGS: >-
diff --git a/ci/common.gitlab-ci.yml b/ci/common.gitlab-ci.yml
index df0367cbd..86061f436 100644
--- a/ci/common.gitlab-ci.yml
+++ b/ci/common.gitlab-ci.yml
@@ -1,6 +1,6 @@
 # Base configuration for linux builds and tests.
 .common:linux:cross:
-  image: ubuntu:20.04
+  image: ubuntu:24.04
   variables:
     EIGEN_CI_TARGET_ARCH: ""
     EIGEN_CI_ADDITIONAL_ARGS: ""
diff --git a/ci/test.linux.gitlab-ci.yml b/ci/test.linux.gitlab-ci.yml
index ec10aeac2..ff6efa3de 100644
--- a/ci/test.linux.gitlab-ci.yml
+++ b/ci/test.linux.gitlab-ci.yml
@@ -91,97 +91,62 @@ test:linux:x86-64:gcc-10:avx512dq:unsupported:
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
-# Clang-6 (minimum on Ubuntu 20.04)
-.test:linux:x86-64:clang-6:default:
+# Clang-14 (modern stable)
+.test:linux:x86-64:clang-14:default:
   extends: .test:linux:x86-64
-  image: ubuntu:20.04
-  needs: [ build:linux:cross:x86-64:clang-6:default ]
+  needs: [ build:linux:cross:x86-64:clang-14:default ]
   variables:
-    EIGEN_CI_INSTALL: g++-8 clang-6.0 lld-6.0
+    EIGEN_CI_INSTALL: clang-14
 
-test:linux:x86-64:clang-6:default:official:
-  extends: .test:linux:x86-64:clang-6:default
+test:linux:x86-64:clang-14:default:official:
+  extends: .test:linux:x86-64:clang-14:default
   variables:
     EIGEN_CI_CTEST_LABEL: Official
 
-test:linux:x86-64:clang-6:default:unsupported:
-  extends: .test:linux:x86-64:clang-6:default
+test:linux:x86-64:clang-14:default:unsupported:
+  extends: .test:linux:x86-64:clang-14:default
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
-# Clang-12 (modern stable)
-.test:linux:x86-64:clang-12:default:
+.test:linux:x86-64:clang-14:avx2:
   extends: .test:linux:x86-64
-  needs: [ build:linux:cross:x86-64:clang-12:default ]
+  needs: [ build:linux:cross:x86-64:clang-14:avx2 ]
   variables:
-    EIGEN_CI_INSTALL: clang-12
+    EIGEN_CI_INSTALL: clang-14
 
-test:linux:x86-64:clang-12:default:official:
-  extends: .test:linux:x86-64:clang-12:default
+test:linux:x86-64:clang-14:avx2:official:
+  extends: .test:linux:x86-64:clang-14:avx2
   variables:
     EIGEN_CI_CTEST_LABEL: Official
 
-test:linux:x86-64:clang-12:default:unsupported:
-  extends: .test:linux:x86-64:clang-12:default
+test:linux:x86-64:clang-14:avx2:unsupported:
+  extends: .test:linux:x86-64:clang-14:avx2
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
-.test:linux:x86-64:clang-12:avx:
+.test:linux:x86-64:clang-14:avx512dq:
   extends: .test:linux:x86-64
-  needs: [ build:linux:cross:x86-64:clang-12:avx ]
+  needs: [ build:linux:cross:x86-64:clang-14:avx512dq ]
   variables:
-    EIGEN_CI_INSTALL: clang-12
-
-test:linux:x86-64:clang-12:avx:official:
-  extends: .test:linux:x86-64:clang-12:avx
-  variables:
-    EIGEN_CI_CTEST_LABEL: Official
-
-test:linux:x86-64:clang-12:avx:unsupported:
-  extends: .test:linux:x86-64:clang-12:avx
-  variables:
-    EIGEN_CI_CTEST_LABEL: Unsupported
-
-.test:linux:x86-64:clang-12:avx2:
-  extends: .test:linux:x86-64
-  needs: [ build:linux:cross:x86-64:clang-12:avx2 ]
-  variables:
-    EIGEN_CI_INSTALL: clang-12
-
-test:linux:x86-64:clang-12:avx2:official:
-  extends: .test:linux:x86-64:clang-12:avx2
-  variables:
-    EIGEN_CI_CTEST_LABEL: Official
-
-test:linux:x86-64:clang-12:avx2:unsupported:
-  extends: .test:linux:x86-64:clang-12:avx2
-  variables:
-    EIGEN_CI_CTEST_LABEL: Unsupported
-
-.test:linux:x86-64:clang-12:avx512dq:
-  extends: .test:linux:x86-64
-  needs: [ build:linux:cross:x86-64:clang-12:avx512dq ]
-  variables:
-    EIGEN_CI_INSTALL: clang-12
+    EIGEN_CI_INSTALL: clang-14
   tags:
     - eigen-runner
     - linux
     - x86-64
     - avx512
 
-test:linux:x86-64:clang-12:avx512dq:official:
-  extends: .test:linux:x86-64:clang-12:avx512dq
+test:linux:x86-64:clang-14:avx512dq:official:
+  extends: .test:linux:x86-64:clang-14:avx512dq
   variables:
     EIGEN_CI_CTEST_LABEL: Official
 
-test:linux:x86-64:clang-12:avx512dq:unsupported:
-  extends: .test:linux:x86-64:clang-12:avx512dq
+test:linux:x86-64:clang-14:avx512dq:unsupported:
+  extends: .test:linux:x86-64:clang-14:avx512dq
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
 # Generic vector extension backend.
 .test:linux:x86-64:clang-19:generic:avx512dq:
-  image: ubuntu:24.04
   extends: .test:linux:x86-64
   needs: [ build:linux:cross:x86-64:clang-19:generic:avx512dq ]
   variables:
@@ -203,7 +168,6 @@ test:linux:x86-64:clang-19:generic:avx512dq:unsupported:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
 .test:linux:x86-64:clang-19:cxx20:nightly:
-  image: ubuntu:24.04
   extends: .test:linux:x86-64
   needs: [ build:linux:cross:x86-64:clang-19:cxx20:nightly ]
   variables:
@@ -227,7 +191,6 @@ test:linux:x86-64:clang-19:cxx20:nightly:unsupported:
 
 .test:linux:x86-64:clang-19:default:asan-ubsan:
   extends: .test:linux:x86-64
-  image: ubuntu:24.04
   variables:
     EIGEN_CI_INSTALL: clang-19 llvm-19
     ASAN_OPTIONS: detect_leaks=0:print_stacktrace=1
@@ -320,19 +283,19 @@ test:linux:arm:gcc-10:default:unsupported:
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
-.test:linux:arm:clang-12:default:
+.test:linux:arm:clang-14:default:
   extends: .test:linux:arm
-  needs: [ build:linux:cross:arm:clang-12:default ]
+  needs: [ build:linux:cross:arm:clang-14:default ]
   variables:
-    EIGEN_CI_CROSS_INSTALL: g++-10-arm-linux-gnueabihf clang-12 qemu-user-static
+    EIGEN_CI_CROSS_INSTALL: g++-10-arm-linux-gnueabihf clang-14 qemu-user-static
 
-test:linux:arm:clang-12:default:official:
-  extends: .test:linux:arm:clang-12:default
+test:linux:arm:clang-14:default:official:
+  extends: .test:linux:arm:clang-14:default
   variables:
     EIGEN_CI_CTEST_LABEL: Official
 
-test:linux:arm:clang-12:default:unsupported:
-  extends: .test:linux:arm:clang-12:default
+test:linux:arm:clang-14:default:unsupported:
+  extends: .test:linux:arm:clang-14:default
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
@@ -362,19 +325,19 @@ test:linux:aarch64:gcc-10:default:unsupported:
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
-.test:linux:aarch64:clang-12:default:
+.test:linux:aarch64:clang-14:default:
   extends: .test:linux:aarch64
-  needs: [ build:linux:cross:aarch64:clang-12:default ]
+  needs: [ build:linux:cross:aarch64:clang-14:default ]
   variables:
-    EIGEN_CI_INSTALL: clang-12
+    EIGEN_CI_INSTALL: clang-14
 
-test:linux:aarch64:clang-12:default:official:
-  extends: .test:linux:aarch64:clang-12:default
+test:linux:aarch64:clang-14:default:official:
+  extends: .test:linux:aarch64:clang-14:default
   variables:
     EIGEN_CI_CTEST_LABEL: Official
 
-test:linux:aarch64:clang-12:default:unsupported:
-  extends: .test:linux:aarch64:clang-12:default
+test:linux:aarch64:clang-14:default:unsupported:
+  extends: .test:linux:aarch64:clang-14:default
   variables:
     EIGEN_CI_CTEST_LABEL: Unsupported
 
@@ -382,7 +345,6 @@ test:linux:aarch64:clang-12:default:unsupported:
 
 .test:linux:ppc64le:
   extends: .test:linux
-  image: ubuntu:24.04
   variables:
     EIGEN_CI_TARGET_ARCH: ppc64le
     EIGEN_CI_CROSS_TARGET_TRIPLE: powerpc64le-linux-gnu
@@ -425,7 +387,6 @@ test:linux:ppc64le:clang-16:default:unsupported:
 
 .test:linux:loongarch64:
   extends: .test:linux
-  image: ubuntu:24.04
   variables:
     EIGEN_CI_TARGET_ARCH: loongarch64
     EIGEN_CI_CROSS_TARGET_TRIPLE: loongarch64-linux-gnu
@@ -436,7 +397,6 @@ test:linux:ppc64le:clang-16:default:unsupported:
 # GCC-14 (Ubuntu 24)
 .test:linux:loongarch64:gcc-14:default:
   extends: .test:linux:loongarch64
-  image: ubuntu:24.04
   needs: [ build:linux:cross:loongarch64:gcc-14:default ]
 
 test:linux:loongarch64:gcc-14:default:official:
@@ -461,9 +421,9 @@ test:linux:x86-64:gcc-10:default:smoketest:
   tags:
     - saas-linux-medium-amd64
 
-test:linux:x86-64:clang-12:default:smoketest:
-  extends: .test:linux:x86-64:clang-12:default
-  needs: [ build:linux:cross:x86-64:clang-12:default:smoketest ]
+test:linux:x86-64:clang-14:default:smoketest:
+  extends: .test:linux:x86-64:clang-14:default
+  needs: [ build:linux:cross:x86-64:clang-14:default:smoketest ]
   variables:
     EIGEN_CI_CTEST_LABEL: smoketest
   rules:
@@ -483,16 +443,16 @@ test:linux:aarch64:gcc-10:default:smoketest:
 
 ##### Sanitizer Smoke Tests ####################################################
 
-test:linux:x86-64:clang-12:sanitizer:smoketest:
-  extends: .test:linux:x86-64:clang-12:default
-  needs: [ build:linux:cross:x86-64:clang-12:sanitizer:smoketest ]
+test:linux:x86-64:clang-14:sanitizer:smoketest:
+  extends: .test:linux:x86-64:clang-14:default
+  needs: [ build:linux:cross:x86-64:clang-14:sanitizer:smoketest ]
   variables:
-    EIGEN_CI_INSTALL: clang-12 llvm-12
+    EIGEN_CI_INSTALL: clang-14 llvm-14
     EIGEN_CI_CTEST_LABEL: smoketest
     EIGEN_CI_CTEST_PARALLEL: "2"
     EIGEN_CI_CTEST_ARGS: --timeout 120
     ASAN_OPTIONS: "detect_leaks=0:halt_on_error=1:abort_on_error=1:allocator_may_return_null=1:print_stacktrace=1:detect_stack_use_after_return=0"
-    ASAN_SYMBOLIZER_PATH: "/usr/lib/llvm-12/bin/llvm-symbolizer"
+    ASAN_SYMBOLIZER_PATH: "/usr/lib/llvm-14/bin/llvm-symbolizer"
     UBSAN_OPTIONS: "halt_on_error=0:print_stacktrace=1"
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"