diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 09038c1e..584e28b7 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -12,7 +12,7 @@
       }
     }
   },
-  "image": "ghcr.io/learning-process/ppc-ubuntu:1.2",
+  "image": "ghcr.io/learning-process/ppc-ubuntu:1.3",
   "name": "Parallel Programming Course",
   "postCreateCommand": "python3 -m pip install -r requirements.txt"
 }
diff --git a/.github/workflows/static-analysis-pr.yml b/.github/workflows/static-analysis-pr.yml
index 78db4657..3e788ec8 100644
--- a/.github/workflows/static-analysis-pr.yml
+++ b/.github/workflows/static-analysis-pr.yml
@@ -123,15 +123,15 @@ jobs:
           -D CMAKE_BUILD_TYPE=RELEASE -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_COMPILE_WARNING_AS_ERROR=ON
           -D PPC_TASKS="${{ needs.ci-scope.outputs.ppc_tasks || 'all' }}"
         env:
-          CC: gcc-14
-          CXX: g++-14
+          CC: gcc-15
+          CXX: g++-15
 
       - name: Build project
         run: |
           cmake --build build --parallel -- --quiet
         env:
-          CC: gcc-14
-          CXX: g++-14
+          CC: gcc-15
+          CXX: g++-15
 
       - name: Show ccache stats
         run: ccache --show-stats
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index a89b5660..01f3106f 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -46,8 +46,8 @@ jobs:
           -D CMAKE_BUILD_TYPE=${{ matrix.build_type }} -DCMAKE_INSTALL_PREFIX=install
           -D PPC_TASKS="${{ inputs.ppc_tasks }}"
         env:
-          CC: gcc-14
-          CXX: g++-14
+          CC: gcc-15
+          CXX: g++-15
       - name: Archive revert list
         uses: actions/upload-artifact@v7
         if: ${{ matrix.os == 'ubuntu-24.04' && matrix.build_type == 'Release' }}
@@ -58,8 +58,8 @@ jobs:
         run: |
           cmake --build build --parallel -- --quiet
         env:
-          CC: gcc-14
-          CXX: g++-14
+          CC: gcc-15
+          CXX: g++-15
       - name: Install project
         run: |
           cmake --build build --target install -- --quiet
@@ -398,7 +398,7 @@ jobs:
         run: |
           mkdir cov-report
           cd build
-          gcovr --gcov-executable `which gcov-14` \
+          gcovr --gcov-executable `which gcov-15` \
                 -r ../ \
                 --exclude '.*3rdparty/.*' \
                 --exclude '/usr/.*' \
diff --git a/docker/CHANGELOG.md b/docker/CHANGELOG.md
index ef510b51..0272ad5a 100644
--- a/docker/CHANGELOG.md
+++ b/docker/CHANGELOG.md
@@ -4,7 +4,7 @@
 
 ### [1.3] - 2026-06-01
 
-- Update base image to Ubuntu 26.04
+- Update base image to Ubuntu 26.04 and switch to gcc-15
 
 ### [1.2] - 2026-02-25
 
diff --git a/docker/ubuntu.Dockerfile b/docker/ubuntu.Dockerfile
index dd9aa314..a4aaed63 100644
--- a/docker/ubuntu.Dockerfile
+++ b/docker/ubuntu.Dockerfile
@@ -15,7 +15,7 @@ RUN set -e \
     libmpich-dev mpich \
     openmpi-bin openmpi-common libopenmpi-dev \
     libomp-dev \
-    gcc-14 g++-14 \
+    gcc-15 g++-15 \
     gcovr zip \
  && wget -q https://apt.llvm.org/llvm.sh \
  && chmod +x llvm.sh \
@@ -24,6 +24,6 @@ RUN set -e \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*
 
-ENV CC=gcc-14 CXX=g++-14
+ENV CC=gcc-15 CXX=g++-15
 
 CMD ["bash"]
diff --git a/docs/locale/en/LC_MESSAGES/user_guide/environment.po b/docs/locale/en/LC_MESSAGES/user_guide/environment.po
index 162c3b6e..9c57fead 100644
--- a/docs/locale/en/LC_MESSAGES/user_guide/environment.po
+++ b/docs/locale/en/LC_MESSAGES/user_guide/environment.po
@@ -80,7 +80,7 @@ msgid "The container includes:"
 msgstr ""
 
 #: ../../../../docs/user_guide/environment.rst:21
-msgid "Ubuntu environment with gcc-14, CMake, MPI, OpenMP"
+msgid "Ubuntu environment with gcc-15, CMake, MPI, OpenMP"
 msgstr ""
 
 #: ../../../../docs/user_guide/environment.rst:22
diff --git a/docs/locale/ru/LC_MESSAGES/user_guide/environment.po b/docs/locale/ru/LC_MESSAGES/user_guide/environment.po
index 50769108..607dd185 100644
--- a/docs/locale/ru/LC_MESSAGES/user_guide/environment.po
+++ b/docs/locale/ru/LC_MESSAGES/user_guide/environment.po
@@ -89,8 +89,8 @@ msgid "The container includes:"
 msgstr "Контейнер включает:"
 
 #: ../../../../docs/user_guide/environment.rst:21
-msgid "Ubuntu environment with gcc-14, CMake, MPI, OpenMP"
-msgstr "Окружение Ubuntu с gcc-14, CMake, MPI, OpenMP"
+msgid "Ubuntu environment with gcc-15, CMake, MPI, OpenMP"
+msgstr "Окружение Ubuntu с gcc-15, CMake, MPI, OpenMP"
 
 #: ../../../../docs/user_guide/environment.rst:22
 msgid "Pre-configured C++ and Python development tools"
diff --git a/docs/user_guide/environment.rst b/docs/user_guide/environment.rst
index 8d6bad46..a8a653a3 100644
--- a/docs/user_guide/environment.rst
+++ b/docs/user_guide/environment.rst
@@ -18,7 +18,7 @@ The easiest way to set up your development environment is using the provided ``.
 3. VS Code will automatically build the container with all dependencies pre-installed
 4. The container includes:
 
-   - Ubuntu environment with gcc-14, CMake, MPI, OpenMP
+   - Ubuntu environment with gcc-15, CMake, MPI, OpenMP
    - Pre-configured C++ and Python development tools
    - All project dependencies ready to use
 
@@ -69,8 +69,6 @@ Install these to match the CI toolchain for static analysis and coverage reports
      sudo apt update && sudo apt install -y clang-tidy-22
      # gcovr via pip (or use your distro package)
      python3 -m pip install gcovr
-     # GCC 14 coverage helper (used in CI)
-     which gcov-14 || echo "Install GCC 14 to use gcov-14"
 
 - macOS (Homebrew):