diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go
index 2918bbd9e..1eaa21402 100644
--- a/pkg/sentry/vfs/mount.go
+++ b/pkg/sentry/vfs/mount.go
@@ -1131,6 +1131,10 @@ func (vfs *VirtualFilesystem) PivotRoot(ctx context.Context, creds *auth.Credent
 	if !vfs.isPathReachable(ctx, newRoot, putOld) {
 		return newRoot, oldRoot, linuxerr.EINVAL
 	}
+	// the new root must be at or underneath the current root.
+	if !vfs.isPathReachable(ctx, oldRoot, newRoot) {
+		return newRoot, oldRoot, linuxerr.EINVAL
+	}
 	// The current root directory must be a mountpoint
 	// (in the case it has been chrooted).
 	if oldRoot.mount.root != oldRoot.dentry {
diff --git a/test/syscalls/linux/pivot_root.cc b/test/syscalls/linux/pivot_root.cc
index d99c36089..998ba4381 100644
--- a/test/syscalls/linux/pivot_root.cc
+++ b/test/syscalls/linux/pivot_root.cc
@@ -23,6 +23,7 @@
 #include <unistd.h>
 
 #include <algorithm>
+#include <functional>
 #include <string>
 #include <vector>
 
@@ -35,6 +36,7 @@
 #include "test/util/capability_util.h"
 #include "test/util/file_descriptor.h"
 #include "test/util/fs_util.h"
+#include "test/util/linux_capability_util.h"
 #include "test/util/logging.h"
 #include "test/util/mount_util.h"
 #include "test/util/multiprocess_util.h"
@@ -47,6 +49,8 @@ namespace testing {
 
 namespace {
 
+constexpr char kTmpfs[] = "tmpfs";
+
 TEST(PivotRootTest, Success) {
   SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
   SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_CHROOT)));
@@ -514,6 +518,37 @@ TEST(PivotRootTest, OnSharedPutOldMountpoint) {
   EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
 }
 
+TEST(PivotRootTest, UnreachableNewRootFails) {
+  SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
+  SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_CHROOT)));
+
+  TempPath outside_root = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
+  ASSERT_THAT(mount("", outside_root.path().c_str(), kTmpfs, 0, ""),
+              SyscallSucceeds());
+  TempPath root =
+      ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(outside_root.path()));
+  ASSERT_THAT(mount("", root.path().c_str(), kTmpfs, 0, ""), SyscallSucceeds());
+  TempPath new_root =
+      ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(root.path()));
+  ASSERT_THAT(mount("", new_root.path().c_str(), kTmpfs, 0, ""),
+              SyscallSucceeds());
+  const std::string new_root_path =
+      absl::StrCat("/", Basename(new_root.path()));
+  TempPath put_old =
+      ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(new_root.path()));
+  const std::string put_old_path =
+      JoinPath(new_root_path, Basename(put_old.path()));
+  ASSERT_THAT(chdir(JoinPath(root.path(), "..").c_str()), SyscallSucceeds());
+
+  const std::function<void()> rest = [&] {
+    TEST_CHECK_SUCCESS(chroot(root.path().c_str()));
+    // "." references the directory outside the chroot.
+    TEST_CHECK_ERRNO(syscall(__NR_pivot_root, ".", put_old_path.c_str()),
+                     EINVAL);
+  };
+  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
+}
+
 }  // namespace
 
 }  // namespace testing