fix: prevent path traversal in delete_files MCP tool

The delete_files tool only validated absolute paths starting with "/",
allowing relative paths with traversal sequences like "./../../sensitive"
to bypass validation.

Now all paths are normalized using path.resolve() before validation,
ensuring both absolute and relative paths with ".." sequences are
properly blocked from accessing files outside the repository root.

.github/workflows/sync-base-action.yml

@@ -94,5 +94,5 @@ jobs:
           echo "✅ Successfully synced \`base-action\` directory to [anthropics/claude-code-base-action](https://github.com/anthropics/claude-code-base-action)" >> $GITHUB_STEP_SUMMARY
           echo "" >> $GITHUB_STEP_SUMMARY
           echo "- **Source commit**: [\`${GITHUB_SHA:0:7}\`](https://github.com/anthropics/claude-code-action/commit/${GITHUB_SHA})" >> $GITHUB_STEP_SUMMARY
-          echo "- **Triggered by**: ${{ github.event_name }}" >> $GITHUB_STEP_SUMMARY
-          echo "- **Actor**: @${{ github.actor }}" >> $GITHUB_STEP_SUMMARY
+          echo "- **Triggered by**: $GITHUB_EVENT_NAME" >> $GITHUB_STEP_SUMMARY
+          echo "- **Actor**: @$GITHUB_ACTOR" >> $GITHUB_STEP_SUMMARY

action.yml

@@ -140,10 +140,12 @@ runs:
     - name: Setup Custom Bun Path
       if: inputs.path_to_bun_executable != ''
       shell: bash
+      env:
+        PATH_TO_BUN_EXECUTABLE: ${{ inputs.path_to_bun_executable }}
       run: |
-        echo "Using custom Bun executable: ${{ inputs.path_to_bun_executable }}"
+        echo "Using custom Bun executable: $PATH_TO_BUN_EXECUTABLE"
         # Add the directory containing the custom executable to PATH
-        BUN_DIR=$(dirname "${{ inputs.path_to_bun_executable }}")
+        BUN_DIR=$(dirname "$PATH_TO_BUN_EXECUTABLE")
         echo "$BUN_DIR" >> "$GITHUB_PATH"
 
     - name: Install Dependencies
@@ -182,6 +184,8 @@ runs:
     - name: Install Base Action Dependencies
       if: steps.prepare.outputs.contains_trigger == 'true'
       shell: bash
+      env:
+        PATH_TO_CLAUDE_CODE_EXECUTABLE: ${{ inputs.path_to_claude_code_executable }}
       run: |
         echo "Installing base-action dependencies..."
         cd ${GITHUB_ACTION_PATH}/base-action
@@ -190,8 +194,8 @@ runs:
         cd -
 
         # Install Claude Code if no custom executable is provided
-        if [ -z "${{ inputs.path_to_claude_code_executable }}" ]; then
-          CLAUDE_CODE_VERSION="2.0.60"
+        if [ -z "$PATH_TO_CLAUDE_CODE_EXECUTABLE" ]; then
+          CLAUDE_CODE_VERSION="2.0.62"
           echo "Installing Claude Code v${CLAUDE_CODE_VERSION}..."
           for attempt in 1 2 3; do
             echo "Installation attempt $attempt..."
@@ -210,9 +214,9 @@ runs:
           echo "Claude Code installed successfully"
           echo "$HOME/.local/bin" >> "$GITHUB_PATH"
         else
-          echo "Using custom Claude Code executable: ${{ inputs.path_to_claude_code_executable }}"
+          echo "Using custom Claude Code executable: $PATH_TO_CLAUDE_CODE_EXECUTABLE"
           # Add the directory containing the custom executable to PATH
-          CLAUDE_DIR=$(dirname "${{ inputs.path_to_claude_code_executable }}")
+          CLAUDE_DIR=$(dirname "$PATH_TO_CLAUDE_CODE_EXECUTABLE")
           echo "$CLAUDE_DIR" >> "$GITHUB_PATH"
         fi
 

base-action/action.yml

@@ -101,10 +101,12 @@ runs:
     - name: Setup Custom Bun Path
       if: inputs.path_to_bun_executable != ''
       shell: bash
+      env:
+        PATH_TO_BUN_EXECUTABLE: ${{ inputs.path_to_bun_executable }}
       run: |
-        echo "Using custom Bun executable: ${{ inputs.path_to_bun_executable }}"
+        echo "Using custom Bun executable: $PATH_TO_BUN_EXECUTABLE"
         # Add the directory containing the custom executable to PATH
-        BUN_DIR=$(dirname "${{ inputs.path_to_bun_executable }}")
+        BUN_DIR=$(dirname "$PATH_TO_BUN_EXECUTABLE")
         echo "$BUN_DIR" >> "$GITHUB_PATH"
 
     - name: Install Dependencies
@@ -115,9 +117,11 @@ runs:
 
     - name: Install Claude Code
       shell: bash
+      env:
+        PATH_TO_CLAUDE_CODE_EXECUTABLE: ${{ inputs.path_to_claude_code_executable }}
       run: |
-        if [ -z "${{ inputs.path_to_claude_code_executable }}" ]; then
-          CLAUDE_CODE_VERSION="2.0.60"
+        if [ -z "$PATH_TO_CLAUDE_CODE_EXECUTABLE" ]; then
+          CLAUDE_CODE_VERSION="2.0.62"
           echo "Installing Claude Code v${CLAUDE_CODE_VERSION}..."
           for attempt in 1 2 3; do
             echo "Installation attempt $attempt..."
@@ -135,9 +139,9 @@ runs:
           done
           echo "Claude Code installed successfully"
         else
-          echo "Using custom Claude Code executable: ${{ inputs.path_to_claude_code_executable }}"
+          echo "Using custom Claude Code executable: $PATH_TO_CLAUDE_CODE_EXECUTABLE"
           # Add the directory containing the custom executable to PATH
-          CLAUDE_DIR=$(dirname "${{ inputs.path_to_claude_code_executable }}")
+          CLAUDE_DIR=$(dirname "$PATH_TO_CLAUDE_CODE_EXECUTABLE")
           echo "$CLAUDE_DIR" >> "$GITHUB_PATH"
         fi
 

base-action/src/parse-sdk-options.ts

@@ -101,7 +101,7 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     env.GITHUB_ACTION_INPUTS = process.env.INPUT_ACTION_INPUTS_PRESENT;
   }
 
-  // Build system prompt option
+  // Build system prompt option - default to claude_code preset
   let systemPrompt: SdkOptions["systemPrompt"];
   if (options.systemPrompt) {
     systemPrompt = options.systemPrompt;
@@ -111,6 +111,12 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
       preset: "claude_code",
       append: options.appendSystemPrompt,
     };
+  } else {
+    // Default to claude_code preset when no custom prompt is specified
+    systemPrompt = {
+      type: "preset",
+      preset: "claude_code",
+    };
   }
 
   // Build SDK options - use merged tools from both direct options and claudeArgs
@@ -130,6 +136,9 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     // Note: allowedTools and disallowedTools have been removed from extraArgs to prevent duplicates
     extraArgs,
     env,
+
+    // Load settings from all sources to pick up CLI-installed plugins, CLAUDE.md, etc.
+    settingSources: ["user", "project", "local"],
   };
 
   return {

base-action/src/run-claude-sdk.ts

@@ -75,6 +75,9 @@ export async function runClaudeWithSdk(
   }
 
   console.log(`Running Claude with prompt from file: ${promptPath}`);
+  // Log SDK options without env (which could contain sensitive data)
+  const { env, ...optionsToLog } = sdkOptions;
+  console.log("SDK options:", JSON.stringify(optionsToLog, null, 2));
 
   const messages: SDKMessage[] = [];
   let resultMessage: SDKResultMessage | undefined;

src/mcp/github-file-ops-server.ts

@@ -4,7 +4,7 @@ import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import { z } from "zod";
 import { readFile, stat } from "fs/promises";
-import { join } from "path";
+import { join, resolve, sep } from "path";
 import { constants } from "fs";
 import fetch from "node-fetch";
 import { GITHUB_API_URL } from "../github/api/config";
@@ -474,20 +474,21 @@ server.tool(
         throw new Error("GITHUB_TOKEN environment variable is required");
       }
 
-      // Convert absolute paths to relative if they match CWD
+      // Normalize all paths and validate they're within the repository root
       const cwd = process.cwd();
       const processedPaths = paths.map((filePath) => {
-        if (filePath.startsWith("/")) {
-          if (filePath.startsWith(cwd)) {
-            // Strip CWD from absolute path
-            return filePath.slice(cwd.length + 1);
-          } else {
-            throw new Error(
-              `Path '${filePath}' must be relative to repository root or within current working directory`,
-            );
-          }
+        // Normalize the path to resolve any .. or . sequences
+        const normalizedPath = resolve(cwd, filePath);
+
+        // Validate the normalized path is within the current working directory
+        if (!normalizedPath.startsWith(cwd + sep)) {
+          throw new Error(
+            `Path '${filePath}' resolves outside the repository root`,
+          );
         }
-        return filePath;
+
+        // Convert to relative path by stripping the cwd prefix
+        return normalizedPath.slice(cwd.length + 1);
       });
 
       // 1. Get the branch reference (create if doesn't exist)