diff --git a/pkg/tools/shell.go b/pkg/tools/shell.go
index 67e2ad257a..198be6d3f1 100644
--- a/pkg/tools/shell.go
+++ b/pkg/tools/shell.go
@@ -5,6 +5,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -12,6 +13,8 @@ import (
 	"runtime"
 	"strings"
 	"time"
+	"unicode"
+	"unicode/utf8"
 
 	"github.com/sipeed/picoclaw/pkg/config"
 	"github.com/sipeed/picoclaw/pkg/constants"
@@ -78,9 +81,13 @@ var (
 		regexp.MustCompile(`\bsource\s+.*\.sh\b`),
 	}
 
-	// absolutePathPattern matches absolute file paths in commands (Unix and Windows).
+	// absolutePathPattern matches path-like substrings in commands (Unix and Windows).
+	// A separate boundary check is applied before treating a match as a filesystem path.
 	absolutePathPattern = regexp.MustCompile(`[A-Za-z]:\\[^\\\"']+|/[^\s\"']+`)
 
+	// fileURIPathPattern matches file:// URIs that may point at local or UNC paths.
+	fileURIPathPattern = regexp.MustCompile(`file://[^\s\"']+`)
+
 	// safePaths are kernel pseudo-devices that are always safe to reference in
 	// commands, regardless of workspace restriction. They contain no user data
 	// and cannot cause destructive writes.
@@ -373,9 +380,54 @@ func (t *ExecTool) guardCommand(command, cwd string) string {
 			return ""
 		}
 
-		matches := absolutePathPattern.FindAllString(cmd, -1)
+		fileURIMatches := fileURIPathPattern.FindAllString(cmd, -1)
+		for _, rawURI := range fileURIMatches {
+			p, ok := fileURIToPath(rawURI, cwdPath)
+			if !ok || safePaths[p] {
+				continue
+			}
+
+			rel, err := filepath.Rel(cwdPath, p)
+			if err != nil {
+				continue
+			}
+
+			if strings.HasPrefix(rel, "..") {
+				return "Command blocked by safety guard (path outside working dir)"
+			}
+		}
+
+		// Web URL schemes whose path components (starting with //) should be exempt
+		// from workspace sandbox checks. file: is intentionally excluded so that
+		// file:// URIs are still validated against the workspace boundary.
+		webSchemes := []string{"http:", "https:", "ftp:", "ftps:", "sftp:", "ssh:", "git:"}
+
+		matchIndices := absolutePathPattern.FindAllStringIndex(cmd, -1)
+
+		for _, loc := range matchIndices {
+			raw := cmd[loc[0]:loc[1]]
+
+			// Skip URL path components that look like they're from web URLs.
+			// When a URL like "https://github.com" is parsed, the regex captures
+			// "//github.com" as a match (the path portion after "https:").
+			// Use the exact match position (loc[0]) so that duplicate //path substrings
+			// in the same command are each evaluated at their own position.
+			if strings.HasPrefix(raw, "//") && loc[0] > 0 {
+				before := cmd[:loc[0]]
+				isWebURL := false
+
+				for _, scheme := range webSchemes {
+					if strings.HasSuffix(before, scheme) {
+						isWebURL = true
+						break
+					}
+				}
+
+				if isWebURL {
+					continue
+				}
+			}
 
-		for _, raw := range matches {
 			p, err := filepath.Abs(raw)
 			if err != nil {
 				continue
@@ -385,6 +437,18 @@ func (t *ExecTool) guardCommand(command, cwd string) string {
 				continue
 			}
 
+			if !isPathBoundary(cmd, loc[0]) {
+				continue
+			}
+
+			if runtime.GOOS == "windows" {
+				pathVolume := filepath.VolumeName(p)
+				cwdVolume := filepath.VolumeName(cwdPath)
+				if pathVolume != "" && cwdVolume != "" && !strings.EqualFold(pathVolume, cwdVolume) {
+					return "Command blocked by safety guard (path outside working dir)"
+				}
+			}
+
 			rel, err := filepath.Rel(cwdPath, p)
 			if err != nil {
 				continue
@@ -399,6 +463,58 @@ func (t *ExecTool) guardCommand(command, cwd string) string {
 	return ""
 }
 
+func isPathBoundary(command string, start int) bool {
+	if start <= 0 {
+		return true
+	}
+
+	r, _ := utf8.DecodeLastRuneInString(command[:start])
+	if unicode.IsSpace(r) {
+		return true
+	}
+
+	return strings.ContainsRune(`"'=<>|&;()[]{},`, r)
+}
+
+func fileURIToPath(rawURI, cwdPath string) (string, bool) {
+	u, err := url.Parse(rawURI)
+	if err != nil || u.Scheme != "file" {
+		return "", false
+	}
+
+	path := u.Path
+	if path == "" {
+		path = u.Opaque
+	}
+
+	if path == "" {
+		return "", false
+	}
+
+	if runtime.GOOS == "windows" && len(path) >= 3 && path[0] == '/' && path[2] == ':' {
+		path = path[1:]
+	}
+
+	if u.Host != "" && u.Host != "localhost" {
+		path = "//" + u.Host + path
+	}
+
+	path = filepath.FromSlash(path)
+
+	if runtime.GOOS == "windows" &&
+		filepath.VolumeName(path) == "" &&
+		(strings.HasPrefix(path, `\`) || strings.HasPrefix(path, `/`)) {
+		path = filepath.VolumeName(cwdPath) + path
+	}
+
+	absPath, err := filepath.Abs(path)
+	if err != nil {
+		return "", false
+	}
+
+	return absPath, true
+}
+
 func (t *ExecTool) SetTimeout(timeout time.Duration) {
 	t.timeout = timeout
 }
diff --git a/pkg/tools/shell_test.go b/pkg/tools/shell_test.go
index 90265e5bdc..b3fc78b0bb 100644
--- a/pkg/tools/shell_test.go
+++ b/pkg/tools/shell_test.go
@@ -489,6 +489,53 @@ func TestShellTool_SafePathsInWorkspaceRestriction(t *testing.T) {
 	}
 }
 
+func TestShellTool_GuardCommand_IgnoresURLPathSegments(t *testing.T) {
+	tmpDir := t.TempDir()
+	tool, err := NewExecTool(tmpDir, true)
+	if err != nil {
+		t.Fatalf("unable to configure exec tool: %s", err)
+	}
+
+	commands := []string{
+		`curl -s "wttr.in/Beijing?T"`,
+		`curl -s https://example.com/api/v1/weather`,
+	}
+
+	for _, cmd := range commands {
+		if got := tool.guardCommand(cmd, tmpDir); got != "" {
+			t.Fatalf("guardCommand(%q) = %q, want empty", cmd, got)
+		}
+	}
+}
+
+func TestShellTool_GuardCommand_BlocksAbsolutePathOutsideWorkspace(t *testing.T) {
+	root := t.TempDir()
+	workspace := filepath.Join(root, "workspace")
+	outsideDir := filepath.Join(root, "outside")
+	outsideFile := filepath.Join(outsideDir, "secret.txt")
+	if err := os.MkdirAll(workspace, 0o755); err != nil {
+		t.Fatalf("failed to create workspace: %v", err)
+	}
+	if err := os.MkdirAll(outsideDir, 0o755); err != nil {
+		t.Fatalf("failed to create outside dir: %v", err)
+	}
+	if err := os.WriteFile(outsideFile, []byte("secret"), 0o644); err != nil {
+		t.Fatalf("failed to create outside file: %v", err)
+	}
+
+	tool, err := NewExecTool(workspace, true)
+	if err != nil {
+		t.Fatalf("unable to configure exec tool: %s", err)
+	}
+
+	if got := tool.guardCommand(
+		`cat "`+outsideFile+`"`,
+		workspace,
+	); !strings.Contains(got, "path outside working dir") {
+		t.Fatalf("guardCommand should block outside path, got %q", got)
+	}
+}
+
 // TestShellTool_CustomAllowPatterns verifies that custom allow patterns exempt
 // commands from deny pattern checks.
 func TestShellTool_CustomAllowPatterns(t *testing.T) {