diff --git a/.bazelrc b/.bazelrc
index 30d9ad9d3..76f81ade4 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -29,7 +29,6 @@ common:linux --test_env=PATH=/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
 common:macos --test_env=PATH=/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
 
 # Pass through some env vars Windows needs to use powershell?
-common:windows --test_env=PATH
 common:windows --test_env=SYSTEMROOT
 common:windows --test_env=COMSPEC
 common:windows --test_env=WINDIR
diff --git a/.github/actions/setup-bazel-ci/action.yml b/.github/actions/setup-bazel-ci/action.yml
index 7c605c60b..008e87c49 100644
--- a/.github/actions/setup-bazel-ci/action.yml
+++ b/.github/actions/setup-bazel-ci/action.yml
@@ -122,6 +122,11 @@ runs:
           }
         }
 
+    - name: Compute cache-stable Windows Bazel PATH
+      if: runner.os == 'Windows'
+      shell: pwsh
+      run: ./.github/scripts/compute-bazel-windows-path.ps1
+
     - name: Enable Git long paths (Windows)
       if: runner.os == 'Windows'
       shell: pwsh
diff --git a/.github/scripts/compute-bazel-windows-path.ps1 b/.github/scripts/compute-bazel-windows-path.ps1
new file mode 100644
index 000000000..6b6bbe046
--- /dev/null
+++ b/.github/scripts/compute-bazel-windows-path.ps1
@@ -0,0 +1,105 @@
+<#
+BuildBuddy cache keys include the action and test environment, so Bazel should
+not inherit the full hosted-runner PATH on Windows. That PATH includes volatile
+tool entries, such as Maven, that can change independently of this repo and
+cause avoidable cache misses.
+
+This script derives a smaller, cache-stable PATH that keeps the Windows
+toolchain entries Bazel-backed CI tasks need: MSVC and Windows SDK paths, Git,
+PowerShell, Node, Python, DotSlash, and the standard Windows system
+directories.
+`setup-bazel-ci` runs this after exporting the MSVC environment, and the script
+publishes the result via `GITHUB_ENV` as `CODEX_BAZEL_WINDOWS_PATH` so later
+steps can pass that explicit PATH to Bazel.
+#>
+
+$stablePathEntries = New-Object System.Collections.Generic.List[string]
+$seenEntries = [System.Collections.Generic.HashSet[string]]::new([System.StringComparer]::OrdinalIgnoreCase)
+$windowsAppsPath = if ([string]::IsNullOrWhiteSpace($env:LOCALAPPDATA)) {
+  $null
+} else {
+  "$($env:LOCALAPPDATA)\Microsoft\WindowsApps"
+}
+$windowsDir = if ($env:WINDIR) {
+  $env:WINDIR
+} elseif ($env:SystemRoot) {
+  $env:SystemRoot
+} else {
+  $null
+}
+
+function Add-StablePathEntry {
+  param([string]$PathEntry)
+
+  if ([string]::IsNullOrWhiteSpace($PathEntry)) {
+    return
+  }
+
+  if ($seenEntries.Add($PathEntry)) {
+    [void]$stablePathEntries.Add($PathEntry)
+  }
+}
+
+foreach ($pathEntry in ($env:PATH -split ';')) {
+  if ([string]::IsNullOrWhiteSpace($pathEntry)) {
+    continue
+  }
+
+  if (
+    $pathEntry -like '*Microsoft Visual Studio*' -or
+    $pathEntry -like '*Windows Kits*' -or
+    $pathEntry -like '*Microsoft SDKs*' -or
+    $pathEntry -like 'C:\Program Files\Git\*' -or
+    $pathEntry -like 'C:\Program Files\PowerShell\*' -or
+    $pathEntry -like 'C:\hostedtoolcache\windows\node\*' -or
+    $pathEntry -like 'C:\hostedtoolcache\windows\Python\*' -or
+    $pathEntry -eq 'D:\a\_temp\install-dotslash\bin' -or
+    ($windowsDir -and ($pathEntry -eq $windowsDir -or $pathEntry -like "${windowsDir}\*"))
+  ) {
+    Add-StablePathEntry $pathEntry
+  }
+}
+
+$gitCommand = Get-Command git -ErrorAction SilentlyContinue
+if ($gitCommand) {
+  Add-StablePathEntry (Split-Path $gitCommand.Source -Parent)
+}
+
+$nodeCommand = Get-Command node -ErrorAction SilentlyContinue
+if ($nodeCommand) {
+  Add-StablePathEntry (Split-Path $nodeCommand.Source -Parent)
+}
+
+$python3Command = Get-Command python3 -ErrorAction SilentlyContinue
+if ($python3Command) {
+  Add-StablePathEntry (Split-Path $python3Command.Source -Parent)
+}
+
+$pythonCommand = Get-Command python -ErrorAction SilentlyContinue
+if ($pythonCommand) {
+  Add-StablePathEntry (Split-Path $pythonCommand.Source -Parent)
+}
+
+$pwshCommand = Get-Command pwsh -ErrorAction SilentlyContinue
+if ($pwshCommand) {
+  Add-StablePathEntry (Split-Path $pwshCommand.Source -Parent)
+}
+
+if ($windowsAppsPath) {
+  Add-StablePathEntry $windowsAppsPath
+}
+
+if ($stablePathEntries.Count -eq 0) {
+  throw 'Failed to derive cache-stable Windows PATH.'
+}
+
+if ([string]::IsNullOrWhiteSpace($env:GITHUB_ENV)) {
+  throw 'GITHUB_ENV must be set.'
+}
+
+$stablePath = $stablePathEntries -join ';'
+Write-Host 'Derived CODEX_BAZEL_WINDOWS_PATH entries:'
+foreach ($pathEntry in $stablePathEntries) {
+  Write-Host "  $pathEntry"
+}
+"CODEX_BAZEL_WINDOWS_PATH=$stablePath" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
diff --git a/.github/scripts/run-bazel-ci.sh b/.github/scripts/run-bazel-ci.sh
index e5376a812..cf2d4ce34 100755
--- a/.github/scripts/run-bazel-ci.sh
+++ b/.github/scripts/run-bazel-ci.sh
@@ -306,7 +306,6 @@ if [[ "${RUNNER_OS:-}" == "Windows" ]]; then
     INCLUDE
     LIB
     LIBPATH
-    PATH
     UCRTVersion
     UniversalCRTSdkDir
     VCINSTALLDIR
@@ -323,6 +322,17 @@ if [[ "${RUNNER_OS:-}" == "Windows" ]]; then
       post_config_bazel_args+=("--action_env=${env_var}" "--host_action_env=${env_var}")
     fi
   done
+
+  if [[ -z "${CODEX_BAZEL_WINDOWS_PATH:-}" ]]; then
+    echo "CODEX_BAZEL_WINDOWS_PATH must be set for Windows Bazel CI." >&2
+    exit 1
+  fi
+
+  post_config_bazel_args+=(
+    "--action_env=PATH=${CODEX_BAZEL_WINDOWS_PATH}"
+    "--host_action_env=PATH=${CODEX_BAZEL_WINDOWS_PATH}"
+    "--test_env=PATH=${CODEX_BAZEL_WINDOWS_PATH}"
+  )
 fi
 
 bazel_console_log="$(mktemp)"