diff --git a/.jules/sentinel.md b/.jules/sentinel.md
new file mode 100644
index 00000000000..8361e83c11c
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,4 @@
+## 2025-06-25 - [Git Argument Injection]
+**Vulnerability:** Argument injection (flag injection) in `git` commands when passing user-controlled strings (like branch names, refs, or repository URLs) as positional arguments.
+**Learning:** Even when using `exec.Command` (which avoids shell injection), some commands like `git` can interpret positional arguments starting with `-` as flags, potentially leading to unauthorized configuration changes or other security risks.
+**Prevention:** Use the `--` separator to explicitly delineate options from positional arguments in `git` commands (e.g., `git checkout <ref> --`). Always place `--` before any argument that could potentially start with a hyphen.
diff --git a/pkg/cli/git.go b/pkg/cli/git.go
index 7493dfabc12..9b9fc6d7312 100644
--- a/pkg/cli/git.go
+++ b/pkg/cli/git.go
@@ -465,7 +465,7 @@ func getCurrentBranch() (string, error) {
 func createAndSwitchBranch(branchName string, verbose bool) error {
 	console.LogVerbose(verbose, "Creating and switching to branch: "+branchName)
 
-	cmd := exec.Command("git", "checkout", "-b", branchName)
+	cmd := exec.Command("git", "checkout", "-b", branchName, "--")
 	if err := cmd.Run(); err != nil {
 		return fmt.Errorf("failed to create and switch to branch %s: %w", branchName, err)
 	}
@@ -477,7 +477,7 @@ func createAndSwitchBranch(branchName string, verbose bool) error {
 func switchBranch(branchName string, verbose bool) error {
 	console.LogVerbose(verbose, "Switching to branch: "+branchName)
 
-	cmd := exec.Command("git", "checkout", branchName)
+	cmd := exec.Command("git", "checkout", branchName, "--")
 	if err := cmd.Run(); err != nil {
 		return fmt.Errorf("failed to switch to branch %s: %w", branchName, err)
 	}
@@ -503,7 +503,7 @@ func commitChanges(message string, verbose bool) error {
 func pushBranch(branchName string, verbose bool) error {
 	console.LogVerbose(verbose, "Pushing branch: "+branchName)
 
-	cmd := exec.Command("git", "push", "-u", "origin", branchName)
+	cmd := exec.Command("git", "push", "-u", "origin", "--", branchName)
 	if err := cmd.Run(); err != nil {
 		return fmt.Errorf("failed to push branch %s: %w", branchName, err)
 	}
diff --git a/pkg/parser/remote_fetch.go b/pkg/parser/remote_fetch.go
index d317a4fb979..4c5f3292152 100644
--- a/pkg/parser/remote_fetch.go
+++ b/pkg/parser/remote_fetch.go
@@ -73,7 +73,7 @@ func getOrCreateListRepoClone(owner, repo, ref, host string) (string, error) {
 		return "", fmt.Errorf("failed to create temp directory: %w", err)
 	}
 
-	cloneCmd := exec.Command("git", "clone", "--depth", "1", "--branch", ref, "--single-branch", "--filter=blob:none", "--no-checkout", repoURL, tmpDir)
+	cloneCmd := exec.Command("git", "clone", "--depth", "1", "--branch", ref, "--single-branch", "--filter=blob:none", "--no-checkout", "--", repoURL, tmpDir)
 	cloneOutput, err := cloneCmd.CombinedOutput()
 	if err != nil {
 		if cleanupErr := os.RemoveAll(tmpDir); cleanupErr != nil {
@@ -458,12 +458,12 @@ func resolveRefToSHAViaGit(owner, repo, ref, host string) (string, error) {
 
 	// Try to resolve the ref using git ls-remote
 	// Format: git ls-remote <repo> <ref>
-	cmd := exec.Command("git", "ls-remote", repoURL, ref)
+	cmd := exec.Command("git", "ls-remote", "--", repoURL, ref)
 	output, err := cmd.Output()
 	if err != nil {
 		// If exact ref doesn't work, try with refs/heads/ and refs/tags/ prefixes
 		for _, prefix := range []string{"refs/heads/", "refs/tags/"} {
-			cmd = exec.Command("git", "ls-remote", repoURL, prefix+ref)
+			cmd = exec.Command("git", "ls-remote", "--", repoURL, prefix+ref)
 			output, err = cmd.Output()
 			if err == nil && len(output) > 0 {
 				break
@@ -625,7 +625,7 @@ func downloadFileViaGit(ctx context.Context, owner, repo, path, ref, host string
 	// git archive command: git archive --remote=<repo> <ref> <path>
 	// #nosec G204 -- repoURL, ref, and path are from workflow import configuration authored by the
 	// developer; exec.Command with separate args (not shell execution) prevents shell injection.
-	cmd := exec.Command("git", "archive", "--remote="+repoURL, ref, path)
+	cmd := exec.Command("git", "archive", "--remote="+repoURL, ref, "--", path)
 	archiveOutput, err := cmd.Output()
 	if err != nil {
 		// If git archive fails, try with git clone + git show as a fallback
@@ -703,24 +703,24 @@ func downloadFileViaGitClone(owner, repo, path, ref, host string) ([]byte, error
 	if isSHA {
 		// For SHA refs, we need to clone without --branch and then checkout the specific commit
 		// Clone with minimal depth and no branch specified
-		cloneCmd = exec.Command("git", "clone", "--depth", "1", "--no-single-branch", repoURL, tmpDir)
+		cloneCmd = exec.Command("git", "clone", "--depth", "1", "--no-single-branch", "--", repoURL, tmpDir)
 		if output, err := cloneCmd.CombinedOutput(); err != nil {
 			// Try without --no-single-branch if the first attempt fails
 			remoteLog.Printf("Clone with --no-single-branch failed, trying full clone: %s", string(output))
-			cloneCmd = exec.Command("git", "clone", repoURL, tmpDir)
+			cloneCmd = exec.Command("git", "clone", "--", repoURL, tmpDir)
 			if output, err := cloneCmd.CombinedOutput(); err != nil {
 				return nil, fmt.Errorf("failed to clone repository: %w\nOutput: %s", err, string(output))
 			}
 		}
 
 		// Now checkout the specific commit
-		checkoutCmd := exec.Command("git", "-C", tmpDir, "checkout", ref)
+		checkoutCmd := exec.Command("git", "-C", tmpDir, "checkout", ref, "--")
 		if output, err := checkoutCmd.CombinedOutput(); err != nil {
 			return nil, fmt.Errorf("failed to checkout commit %s: %w\nOutput: %s", ref, err, string(output))
 		}
 	} else {
 		// For branch/tag refs, use --branch flag
-		cloneCmd = exec.Command("git", "clone", "--depth", "1", "--branch", ref, repoURL, tmpDir)
+		cloneCmd = exec.Command("git", "clone", "--depth", "1", "--branch", ref, "--", repoURL, tmpDir)
 		if output, err := cloneCmd.CombinedOutput(); err != nil {
 			return nil, fmt.Errorf("failed to clone repository: %w\nOutput: %s", err, string(output))
 		}
@@ -1144,7 +1144,7 @@ func listDirAllFilesViaGitForHost(owner, repo, ref, dirPath, host string) ([]str
 		return nil, err
 	}
 
-	lsTreeCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "-r", "--name-only", "HEAD", dirPath+"/")
+	lsTreeCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "-r", "--name-only", "HEAD", "--", dirPath+"/")
 	lsTreeOutput, err := lsTreeCmd.CombinedOutput()
 	if err != nil {
 		remoteLog.Printf("Failed to list dir files: %s", string(lsTreeOutput))
@@ -1283,7 +1283,7 @@ func listDirAllFilesRecursivelyViaGitForHost(owner, repo, ref, dirPath, host str
 
 	// Normalise dirPath so it never has a trailing slash before we append one.
 	cleanDirPath := strings.TrimRight(dirPath, "/")
-	lsTreeCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "-r", "--name-only", "HEAD", cleanDirPath+"/")
+	lsTreeCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "-r", "--name-only", "HEAD", "--", cleanDirPath+"/")
 	lsTreeOutput, err := lsTreeCmd.CombinedOutput()
 	if err != nil {
 		remoteLog.Printf("Failed to list dir files recursively: %s", string(lsTreeOutput))
@@ -1404,7 +1404,7 @@ func listDirSubdirsViaGitForHost(owner, repo, ref, dirPath, host string) ([]stri
 	}
 
 	// Use ls-tree -d to list only direct subdirectory entries.
-	lsTreeDirsCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "--name-only", "-d", "HEAD", dirPath+"/")
+	lsTreeDirsCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "--name-only", "-d", "HEAD", "--", dirPath+"/")
 	lsTreeDirsOutput, err := lsTreeDirsCmd.CombinedOutput()
 	if err != nil {
 		remoteLog.Printf("Failed to list tree subdirs: %s", string(lsTreeDirsOutput))
@@ -1475,7 +1475,7 @@ func listWorkflowFilesViaGitForHost(owner, repo, ref, workflowPath, host string)
 
 	// Do a minimal clone using filter=blob:none for faster cloning (metadata only, no blobs)
 	// Use --depth=1 for shallow clone and --no-checkout to skip checkout initially
-	cloneCmd := exec.Command("git", "clone", "--depth", "1", "--branch", ref, "--single-branch", "--filter=blob:none", "--no-checkout", repoURL, tmpDir)
+	cloneCmd := exec.Command("git", "clone", "--depth", "1", "--branch", ref, "--single-branch", "--filter=blob:none", "--no-checkout", "--", repoURL, tmpDir)
 	cloneOutput, err := cloneCmd.CombinedOutput()
 	if err != nil {
 		remoteLog.Printf("Failed to clone repository: %s", string(cloneOutput))
@@ -1483,7 +1483,7 @@ func listWorkflowFilesViaGitForHost(owner, repo, ref, workflowPath, host string)
 	}
 
 	// Use git ls-tree to list files in the specified workflows directory
-	lsTreeCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "-r", "--name-only", "HEAD", workflowPath+"/")
+	lsTreeCmd := exec.Command("git", "-C", tmpDir, "ls-tree", "-r", "--name-only", "HEAD", "--", workflowPath+"/")
 	lsTreeOutput, err := lsTreeCmd.CombinedOutput()
 	if err != nil {
 		remoteLog.Printf("Failed to list files: %s", string(lsTreeOutput))