diff --git a/.github/workflows/_build-container.yml b/.github/workflows/_build-container.yml
index 6025d95..4a3d6aa 100644
--- a/.github/workflows/_build-container.yml
+++ b/.github/workflows/_build-container.yml
@@ -22,7 +22,7 @@ permissions:
 
 jobs:
   build:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
diff --git a/.github/workflows/_upload-scripts.yml b/.github/workflows/_upload-scripts.yml
index 4ac37fc..517e117 100644
--- a/.github/workflows/_upload-scripts.yml
+++ b/.github/workflows/_upload-scripts.yml
@@ -21,7 +21,7 @@ permissions:
 
 jobs:
   upload:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
diff --git a/.github/workflows/badgesort.yml b/.github/workflows/badgesort.yml
index 4d5ee84..ebbe322 100644
--- a/.github/workflows/badgesort.yml
+++ b/.github/workflows/badgesort.yml
@@ -19,7 +19,7 @@ concurrency:
 jobs:
   badgesort:
     name: BadgeSort
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: write
     steps:
diff --git a/.github/workflows/e2e-install.yml b/.github/workflows/e2e-install.yml
index 3d84782..7d97350 100644
--- a/.github/workflows/e2e-install.yml
+++ b/.github/workflows/e2e-install.yml
@@ -28,7 +28,7 @@ jobs:
   e2e-linux:
     name: E2E install (Linux)
     if: github.event.action != 'closed'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     services:
       vaultwarden:
         image: vaultwarden/server:latest@sha256:efb3cde962015fcc036b2ea625242248611943b27212ebf4392841fb30fad055
diff --git a/.github/workflows/megalinter.yml b/.github/workflows/megalinter.yml
index 9caf194..1edad79 100644
--- a/.github/workflows/megalinter.yml
+++ b/.github/workflows/megalinter.yml
@@ -18,7 +18,7 @@ concurrency:
 jobs:
   megalinter:
     name: MegaLinter
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     if: github.event.action != 'closed' && (github.event_name == 'pull_request' || !contains(github.actor, '[bot]'))
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 8c8ce96..aa3d044 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -18,7 +18,7 @@ env:
 
 jobs:
   release-please:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: write
       pull-requests: write
diff --git a/.github/workflows/wiki-sync.yml b/.github/workflows/wiki-sync.yml
index b93850c..a05765f 100644
--- a/.github/workflows/wiki-sync.yml
+++ b/.github/workflows/wiki-sync.yml
@@ -18,7 +18,7 @@ concurrency:
 
 jobs:
   sync-wiki:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
diff --git a/.mega-linter.yml b/.mega-linter.yml
index 2334d8b..761974f 100644
--- a/.mega-linter.yml
+++ b/.mega-linter.yml
@@ -1,4 +1,3 @@
----
 # Bundled MegaLinter pylint rc is incompatible with pylint 4.x (removed options).
 DISABLE:
   - COPYPASTE
@@ -52,3 +51,9 @@ REPOSITORY_KICS_ARGUMENTS: "--exclude-paths .github/workflows/e2e-install.yml"
 # aborts with a 401 and is reported as an error.
 ACTION_ZIZMOR_UNSECURED_ENV_VARIABLES:
   - GITHUB_TOKEN
+
+# actionlint v1.7.12 does not include ubuntu-26.04 in its known GitHub-hosted
+# runner label list; the runner is valid (released April 2026) but the actionlint
+# database lags new GitHub runner releases. Suppress the false positive until
+# MegaLinter ships a newer actionlint that knows about ubuntu-26.04.
+ACTION_ACTIONLINT_ARGUMENTS: "-ignore 'label .ubuntu-26.04. is unknown'"