fix: prevent command injection in workflow example files

Fixes command injection vulnerabilities in example workflow files by using
environment variables instead of direct template expansion in shell commands.

This prevents malicious branch names containing command substitution syntax
like $(cmd) from being executed by the shell.

Files fixed:
- examples/ci-failure-auto-fix.yml: github.event.workflow_run.head_branch
- examples/test-failure-analysis.yml: github.event.workflow_run.name and head_branch

.github/workflows/claude.yml

@@ -36,4 +36,4 @@ jobs:
           anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
           claude_args: |
             --allowedTools "Bash(bun install),Bash(bun test:*),Bash(bun run format),Bash(bun typecheck)"
-            --model "claude-opus-4-5"
+            --model "claude-opus-4-1-20250805"

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

@@ -12,79 +12,12 @@ export type ParsedSdkOptions = {
 };
 
 // Flags that should accumulate multiple values instead of overwriting
-// Include both camelCase and hyphenated variants for CLI compatibility
+const ACCUMULATING_FLAGS = new Set(["allowedTools", "disallowedTools"]);
-const ACCUMULATING_FLAGS = new Set([
-  "allowedTools",
-  "allowed-tools",
-  "disallowedTools",
-  "disallowed-tools",
-  "mcp-config",
-]);
-
-// Delimiter used to join accumulated flag values
-const ACCUMULATE_DELIMITER = "\x00";
-
-type McpConfig = {
-  mcpServers?: Record<string, unknown>;
-};
-
-/**
- * Merge multiple MCP config values into a single config.
- * Each config can be a JSON string or a file path.
- * For JSON strings, mcpServers objects are merged.
- * For file paths, they are kept as-is (user's file takes precedence and is used last).
- */
-function mergeMcpConfigs(configValues: string[]): string {
-  const merged: McpConfig = { mcpServers: {} };
-  let lastFilePath: string | null = null;
-
-  for (const config of configValues) {
-    const trimmed = config.trim();
-    if (!trimmed) continue;
-
-    // Check if it's a JSON string (starts with {) or a file path
-    if (trimmed.startsWith("{")) {
-      try {
-        const parsed = JSON.parse(trimmed) as McpConfig;
-        if (parsed.mcpServers) {
-          Object.assign(merged.mcpServers!, parsed.mcpServers);
-        }
-      } catch {
-        // If JSON parsing fails, treat as file path
-        lastFilePath = trimmed;
-      }
-    } else {
-      // It's a file path - store it to handle separately
-      lastFilePath = trimmed;
-    }
-  }
-
-  // If we have file paths, we need to keep the merged JSON and let the file
-  // be handled separately. Since we can only return one value, merge what we can.
-  // If there's a file path, we need a different approach - read the file at runtime.
-  // For now, if there's a file path, we'll stringify the merged config.
-  // The action prepends its config as JSON, so we can safely merge inline JSON configs.
-
-  // If no inline configs were found (all file paths), return the last file path
-  if (Object.keys(merged.mcpServers!).length === 0 && lastFilePath) {
-    return lastFilePath;
-  }
-
-  // Note: If user passes a file path, we cannot merge it at parse time since
-  // we don't have access to the file system here. The action's built-in MCP
-  // servers are always passed as inline JSON, so they will be merged.
-  // If user also passes inline JSON, it will be merged.
-  // If user passes a file path, they should ensure it includes all needed servers.
-
-  return JSON.stringify(merged);
-}
 
 /**
  * Parse claudeArgs string into extraArgs record for SDK pass-through
  * The SDK/CLI will handle --mcp-config, --json-schema, etc.
- * For allowedTools and disallowedTools, multiple occurrences are accumulated (null-char joined).
+ * For allowedTools and disallowedTools, multiple occurrences are accumulated (comma-joined).
- * Accumulating flags also consume all consecutive non-flag values
- * (e.g., --allowed-tools "Tool1" "Tool2" "Tool3" captures all three).
  */
 function parseClaudeArgsToExtraArgs(
   claudeArgs?: string,
@@ -104,25 +37,13 @@ function parseClaudeArgsToExtraArgs(
 
       // Check if next arg is a value (not another flag)
       if (nextArg && !nextArg.startsWith("--")) {
-        // For accumulating flags, consume all consecutive non-flag values
+        // For accumulating flags, join multiple values with commas
-        // This handles: --allowed-tools "Tool1" "Tool2" "Tool3"
+        if (ACCUMULATING_FLAGS.has(flag) && result[flag]) {
-        if (ACCUMULATING_FLAGS.has(flag)) {
+          result[flag] = `${result[flag]},${nextArg}`;
-          const values: string[] = [];
-          while (i + 1 < args.length && !args[i + 1]?.startsWith("--")) {
-            i++;
-            values.push(args[i]!);
-          }
-          const joinedValues = values.join(ACCUMULATE_DELIMITER);
-          if (result[flag]) {
-            result[flag] =
-              `${result[flag]}${ACCUMULATE_DELIMITER}${joinedValues}`;
-          } else {
-            result[flag] = joinedValues;
-          }
         } else {
           result[flag] = nextArg;
-          i++; // Skip the value
         }
+        i++; // Skip the value
       } else {
         result[flag] = null; // Boolean flag
       }
@@ -147,23 +68,12 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
   // Detect if --json-schema is present (for hasJsonSchema flag)
   const hasJsonSchema = "json-schema" in extraArgs;
 
-  // Extract and merge allowedTools from all sources:
+  // Extract and merge allowedTools from both sources:
   // 1. From extraArgs (parsed from claudeArgs - contains tag mode's tools)
-  //    - Check both camelCase (--allowedTools) and hyphenated (--allowed-tools) variants
   // 2. From options.allowedTools (direct input - may be undefined)
   // This prevents duplicate flags being overwritten when claudeArgs contains --allowedTools
-  const allowedToolsValues = [
+  const extraArgsAllowedTools = extraArgs["allowedTools"]
-    extraArgs["allowedTools"],
+    ? extraArgs["allowedTools"].split(",").map((t) => t.trim())
-    extraArgs["allowed-tools"],
-  ]
-    .filter(Boolean)
-    .join(ACCUMULATE_DELIMITER);
-  const extraArgsAllowedTools = allowedToolsValues
-    ? allowedToolsValues
-        .split(ACCUMULATE_DELIMITER)
-        .flatMap((v) => v.split(","))
-        .map((t) => t.trim())
-        .filter(Boolean)
     : [];
   const directAllowedTools = options.allowedTools
     ? options.allowedTools.split(",").map((t) => t.trim())
@@ -172,21 +82,10 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     ...new Set([...extraArgsAllowedTools, ...directAllowedTools]),
   ];
   delete extraArgs["allowedTools"];
-  delete extraArgs["allowed-tools"];
 
-  // Same for disallowedTools - check both camelCase and hyphenated variants
+  // Same for disallowedTools
-  const disallowedToolsValues = [
+  const extraArgsDisallowedTools = extraArgs["disallowedTools"]
-    extraArgs["disallowedTools"],
+    ? extraArgs["disallowedTools"].split(",").map((t) => t.trim())
-    extraArgs["disallowed-tools"],
-  ]
-    .filter(Boolean)
-    .join(ACCUMULATE_DELIMITER);
-  const extraArgsDisallowedTools = disallowedToolsValues
-    ? disallowedToolsValues
-        .split(ACCUMULATE_DELIMITER)
-        .flatMap((v) => v.split(","))
-        .map((t) => t.trim())
-        .filter(Boolean)
     : [];
   const directDisallowedTools = options.disallowedTools
     ? options.disallowedTools.split(",").map((t) => t.trim())
@@ -195,17 +94,6 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     ...new Set([...extraArgsDisallowedTools, ...directDisallowedTools]),
   ];
   delete extraArgs["disallowedTools"];
-  delete extraArgs["disallowed-tools"];
-
-  // Merge multiple --mcp-config values by combining their mcpServers objects
-  // The action prepends its config (github_comment, github_ci, etc.) as inline JSON,
-  // and users may provide their own config as inline JSON or file path
-  if (extraArgs["mcp-config"]) {
-    const mcpConfigValues = extraArgs["mcp-config"].split(ACCUMULATE_DELIMITER);
-    if (mcpConfigValues.length > 1) {
-      extraArgs["mcp-config"] = mergeMcpConfigs(mcpConfigValues);
-    }
-  }
 
   // Build custom environment
   const env: Record<string, string | undefined> = { ...process.env };

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

@@ -108,48 +108,6 @@ describe("parseSdkOptions", () => {
       expect(result.sdkOptions.extraArgs?.["allowedTools"]).toBeUndefined();
       expect(result.sdkOptions.extraArgs?.["model"]).toBe("claude-3-5-sonnet");
     });
-
-    test("should handle hyphenated --allowed-tools flag", () => {
-      const options: ClaudeOptions = {
-        claudeArgs: '--allowed-tools "Edit,Read,Write"',
-      };
-
-      const result = parseSdkOptions(options);
-
-      expect(result.sdkOptions.allowedTools).toEqual(["Edit", "Read", "Write"]);
-      expect(result.sdkOptions.extraArgs?.["allowed-tools"]).toBeUndefined();
-    });
-
-    test("should accumulate multiple --allowed-tools flags (hyphenated)", () => {
-      // This is the exact scenario from issue #746
-      const options: ClaudeOptions = {
-        claudeArgs:
-          '--allowed-tools "Bash(git log:*)" "Bash(git diff:*)" "Bash(git fetch:*)" "Bash(gh pr:*)"',
-      };
-
-      const result = parseSdkOptions(options);
-
-      expect(result.sdkOptions.allowedTools).toEqual([
-        "Bash(git log:*)",
-        "Bash(git diff:*)",
-        "Bash(git fetch:*)",
-        "Bash(gh pr:*)",
-      ]);
-    });
-
-    test("should handle mixed camelCase and hyphenated allowedTools flags", () => {
-      const options: ClaudeOptions = {
-        claudeArgs: '--allowedTools "Edit,Read" --allowed-tools "Write,Glob"',
-      };
-
-      const result = parseSdkOptions(options);
-
-      // Both should be merged - note: order depends on which key is found first
-      expect(result.sdkOptions.allowedTools).toContain("Edit");
-      expect(result.sdkOptions.allowedTools).toContain("Read");
-      expect(result.sdkOptions.allowedTools).toContain("Write");
-      expect(result.sdkOptions.allowedTools).toContain("Glob");
-    });
   });
 
   describe("disallowedTools merging", () => {
@@ -176,129 +134,19 @@ describe("parseSdkOptions", () => {
     });
   });
 
-  describe("mcp-config merging", () => {
-    test("should pass through single mcp-config in extraArgs", () => {
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config '{"mcpServers":{"server1":{"command":"cmd1"}}}'`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      expect(result.sdkOptions.extraArgs?.["mcp-config"]).toBe(
-        '{"mcpServers":{"server1":{"command":"cmd1"}}}',
-      );
-    });
-
-    test("should merge multiple mcp-config flags with inline JSON", () => {
-      // Simulates action prepending its config, then user providing their own
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config '{"mcpServers":{"github_comment":{"command":"node","args":["server.js"]}}}' --mcp-config '{"mcpServers":{"user_server":{"command":"custom","args":["run"]}}}'`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      const mcpConfig = JSON.parse(
-        result.sdkOptions.extraArgs?.["mcp-config"] as string,
-      );
-      expect(mcpConfig.mcpServers).toHaveProperty("github_comment");
-      expect(mcpConfig.mcpServers).toHaveProperty("user_server");
-      expect(mcpConfig.mcpServers.github_comment.command).toBe("node");
-      expect(mcpConfig.mcpServers.user_server.command).toBe("custom");
-    });
-
-    test("should merge three mcp-config flags", () => {
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config '{"mcpServers":{"server1":{"command":"cmd1"}}}' --mcp-config '{"mcpServers":{"server2":{"command":"cmd2"}}}' --mcp-config '{"mcpServers":{"server3":{"command":"cmd3"}}}'`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      const mcpConfig = JSON.parse(
-        result.sdkOptions.extraArgs?.["mcp-config"] as string,
-      );
-      expect(mcpConfig.mcpServers).toHaveProperty("server1");
-      expect(mcpConfig.mcpServers).toHaveProperty("server2");
-      expect(mcpConfig.mcpServers).toHaveProperty("server3");
-    });
-
-    test("should handle mcp-config file path when no inline JSON exists", () => {
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config /tmp/user-mcp-config.json`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      expect(result.sdkOptions.extraArgs?.["mcp-config"]).toBe(
-        "/tmp/user-mcp-config.json",
-      );
-    });
-
-    test("should merge inline JSON configs when file path is also present", () => {
-      // When action provides inline JSON and user provides a file path,
-      // the inline JSON configs should be merged (file paths cannot be merged at parse time)
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config '{"mcpServers":{"github_comment":{"command":"node"}}}' --mcp-config '{"mcpServers":{"github_ci":{"command":"node"}}}' --mcp-config /tmp/user-config.json`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      // The inline JSON configs should be merged
-      const mcpConfig = JSON.parse(
-        result.sdkOptions.extraArgs?.["mcp-config"] as string,
-      );
-      expect(mcpConfig.mcpServers).toHaveProperty("github_comment");
-      expect(mcpConfig.mcpServers).toHaveProperty("github_ci");
-    });
-
-    test("should handle mcp-config with other flags", () => {
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config '{"mcpServers":{"server1":{}}}' --model claude-3-5-sonnet --mcp-config '{"mcpServers":{"server2":{}}}'`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      const mcpConfig = JSON.parse(
-        result.sdkOptions.extraArgs?.["mcp-config"] as string,
-      );
-      expect(mcpConfig.mcpServers).toHaveProperty("server1");
-      expect(mcpConfig.mcpServers).toHaveProperty("server2");
-      expect(result.sdkOptions.extraArgs?.["model"]).toBe("claude-3-5-sonnet");
-    });
-
-    test("should handle real-world scenario: action config + user config", () => {
-      // This is the exact scenario from the bug report
-      const actionConfig = JSON.stringify({
-        mcpServers: {
-          github_comment: {
-            command: "node",
-            args: ["github-comment-server.js"],
-          },
-          github_ci: { command: "node", args: ["github-ci-server.js"] },
-        },
-      });
-      const userConfig = JSON.stringify({
-        mcpServers: {
-          my_custom_server: { command: "python", args: ["server.py"] },
-        },
-      });
-
-      const options: ClaudeOptions = {
-        claudeArgs: `--mcp-config '${actionConfig}' --mcp-config '${userConfig}'`,
-      };
-
-      const result = parseSdkOptions(options);
-
-      const mcpConfig = JSON.parse(
-        result.sdkOptions.extraArgs?.["mcp-config"] as string,
-      );
-      // All servers should be present
-      expect(mcpConfig.mcpServers).toHaveProperty("github_comment");
-      expect(mcpConfig.mcpServers).toHaveProperty("github_ci");
-      expect(mcpConfig.mcpServers).toHaveProperty("my_custom_server");
-    });
-  });
-
   describe("other extraArgs passthrough", () => {
+    test("should pass through mcp-config in extraArgs", () => {
+      const options: ClaudeOptions = {
+        claudeArgs: `--mcp-config '{"mcpServers":{}}' --allowedTools "Edit"`,
+      };
+
+      const result = parseSdkOptions(options);
+
+      expect(result.sdkOptions.extraArgs?.["mcp-config"]).toBe(
+        '{"mcpServers":{}}',
+      );
+    });
+
     test("should pass through json-schema in extraArgs", () => {
       const options: ClaudeOptions = {
         claudeArgs: `--json-schema '{"type":"object"}'`,

examples/ci-failure-auto-fix.yml

@@ -35,8 +35,11 @@ jobs:
 
       - name: Create fix branch
         id: branch
+        env:
+          SOURCE_BRANCH: ${{ github.event.workflow_run.head_branch }}
+          RUN_ID: ${{ github.run_id }}
         run: |
-          BRANCH_NAME="claude-auto-fix-ci-${{ github.event.workflow_run.head_branch }}-${{ github.run_id }}"
+          BRANCH_NAME="claude-auto-fix-ci-${SOURCE_BRANCH}-${RUN_ID}"
           git checkout -b "$BRANCH_NAME"
           echo "branch_name=$BRANCH_NAME" >> $GITHUB_OUTPUT
 

examples/test-failure-analysis.yml

@@ -53,6 +53,8 @@ jobs:
           fromJSON(steps.detect.outputs.structured_output).confidence >= 0.7
         env:
           GH_TOKEN: ${{ github.token }}
+          WORKFLOW_NAME: ${{ github.event.workflow_run.name }}
+          HEAD_BRANCH: ${{ github.event.workflow_run.head_branch }}
         run: |
           OUTPUT='${{ steps.detect.outputs.structured_output }}'
           CONFIDENCE=$(echo "$OUTPUT" | jq -r '.confidence')
@@ -63,8 +65,8 @@ jobs:
           echo ""
           echo "Triggering automatic retry..."
 
-          gh workflow run "${{ github.event.workflow_run.name }}" \
+          gh workflow run "$WORKFLOW_NAME" \
-            --ref "${{ github.event.workflow_run.head_branch }}"
+            --ref "$HEAD_BRANCH"
 
       # Low confidence flaky detection - skip retry
       - name: Low confidence detection
@@ -83,13 +85,14 @@ jobs:
         if: github.event.workflow_run.event == 'pull_request'
         env:
           GH_TOKEN: ${{ github.token }}
+          HEAD_BRANCH: ${{ github.event.workflow_run.head_branch }}
         run: |
           OUTPUT='${{ steps.detect.outputs.structured_output }}'
           IS_FLAKY=$(echo "$OUTPUT" | jq -r '.is_flaky')
           CONFIDENCE=$(echo "$OUTPUT" | jq -r '.confidence')
           SUMMARY=$(echo "$OUTPUT" | jq -r '.summary')
 
-          pr_number=$(gh pr list --head "${{ github.event.workflow_run.head_branch }}" --json number --jq '.[0].number')
+          pr_number=$(gh pr list --head "$HEAD_BRANCH" --json number --jq '.[0].number')
 
           if [ -n "$pr_number" ]; then
             if [ "$IS_FLAKY" = "true" ]; then