diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index a54d75b8..556bc371 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -50,4 +50,4 @@ jobs:
           file: ./docker/ubuntu.Dockerfile
           platforms: linux/amd64,linux/arm64
           push: ${{ github.ref == 'refs/heads/master' }}
-          tags: ghcr.io/learning-process/ppc-ubuntu:1.2
+          tags: ghcr.io/learning-process/ppc-ubuntu:1.3
diff --git a/.github/workflows/perf.yml b/.github/workflows/perf.yml
index fceede49..339fb641 100644
--- a/.github/workflows/perf.yml
+++ b/.github/workflows/perf.yml
@@ -11,7 +11,7 @@ jobs:
   ubuntu-gcc-build-perf-stats:
     runs-on: ubuntu-24.04
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index 3e1e3a63..8313660e 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -31,7 +31,7 @@ jobs:
   pre-commit:
     runs-on: ubuntu-24.04
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/static-analysis-pr.yml b/.github/workflows/static-analysis-pr.yml
index de6bfa1d..073391bb 100644
--- a/.github/workflows/static-analysis-pr.yml
+++ b/.github/workflows/static-analysis-pr.yml
@@ -28,7 +28,7 @@ jobs:
   clang-tidy:
     runs-on: ubuntu-24.04
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -77,7 +77,7 @@ jobs:
       - clang-tidy
     runs-on: ubuntu-24.04
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 8203fb53..d3a082c3 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -17,7 +17,7 @@ jobs:
   gcc-build:
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -71,7 +71,7 @@ jobs:
       - gcc-build
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -103,7 +103,7 @@ jobs:
       - gcc-test
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -127,7 +127,7 @@ jobs:
   clang-build:
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -172,7 +172,7 @@ jobs:
       - clang-build
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -204,7 +204,7 @@ jobs:
       - clang-test
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -230,7 +230,7 @@ jobs:
       - clang-build
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -277,7 +277,7 @@ jobs:
       - clang-sanitizer-build
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -315,7 +315,7 @@ jobs:
       - clang-sanitizer-test
     runs-on: ${{ matrix.os }}
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
@@ -348,7 +348,7 @@ jobs:
       issues: write
       pull-requests: write
     container:
-      image: ghcr.io/learning-process/ppc-ubuntu:1.2
+      image: ghcr.io/learning-process/ppc-ubuntu:1.3
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
diff --git a/docker/CHANGELOG.md b/docker/CHANGELOG.md
index 94a2fc5e..ef510b51 100644
--- a/docker/CHANGELOG.md
+++ b/docker/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## ppc-ubuntu
 
+### [1.3] - 2026-06-01
+
+- Update base image to Ubuntu 26.04
+
 ### [1.2] - 2026-02-25
 
 - Update LLVM version to 22
diff --git a/docker/README.md b/docker/README.md
index c7efccac..c0bd3bde 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -6,7 +6,7 @@
 
 ## Build
 
-Build multi-architecture Ubuntu 24.04 development image:
+Build multi-architecture Ubuntu 26.04 development image:
 
 ```bash
 docker buildx build --platform linux/amd64,linux/arm64 -t ghcr.io/learning-process/ppc-ubuntu:latest -f ./ubuntu.Dockerfile .
diff --git a/docker/ubuntu.Dockerfile b/docker/ubuntu.Dockerfile
index 66fae42d..dd9aa314 100644
--- a/docker/ubuntu.Dockerfile
+++ b/docker/ubuntu.Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:24.04
+FROM ubuntu:26.04
 
 ENV DEBIAN_FRONTEND=noninteractive