diff --git a/bin/omarchy-dev-link b/bin/omarchy-dev-link
index b09473b547d..1af65d1d464 100755
--- a/bin/omarchy-dev-link
+++ b/bin/omarchy-dev-link
@@ -92,7 +92,10 @@ done
 # Staged and parsed before anything is installed: a sudoers file sudo refuses to
 # read takes every rule after it down with it, including the %wheel grant, and
 # the password prompt needed to undo that is on the other side of the breakage.
-staged_sudoers=$(mktemp)
+# Keep the draft out of world-writable /tmp; visudo -cf reads it before install.
+stage_dir="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+mkdir -m 700 -p "$stage_dir"
+staged_sudoers=$(mktemp "$stage_dir/omarchy-dev-path.XXXXXX")
 trap 'rm -f "$staged_sudoers"' EXIT
 
 {
diff --git a/bin/omarchy-hyprland-monitor-watch b/bin/omarchy-hyprland-monitor-watch
index 33e8f2c5999..871dc115b82 100755
--- a/bin/omarchy-hyprland-monitor-watch
+++ b/bin/omarchy-hyprland-monitor-watch
@@ -3,8 +3,10 @@
 # omarchy:summary=Watch Hyprland monitor events and recover monitor toggles when a monitor is removed
 
 SOCKET="$XDG_RUNTIME_DIR/hypr/$HYPRLAND_INSTANCE_SIGNATURE/.socket2.sock"
-LOCK="${XDG_RUNTIME_DIR:-/tmp}/omarchy-monitor-clamshell.lock"
-MODELESS_LOCK="${XDG_RUNTIME_DIR:-/tmp}/omarchy-monitor-modeless.lock"
+LOCK_DIR="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+mkdir -m 700 -p "$LOCK_DIR"
+LOCK="$LOCK_DIR/omarchy-monitor-clamshell.lock"
+MODELESS_LOCK="$LOCK_DIR/omarchy-monitor-modeless.lock"
 
 sync_clamshell() {
   (
diff --git a/bin/omarchy-menu-images b/bin/omarchy-menu-images
index 8305cb0fdd7..4e0cfa59763 100755
--- a/bin/omarchy-menu-images
+++ b/bin/omarchy-menu-images
@@ -72,10 +72,12 @@ if (( ${#image_dirs[@]} == 0 )); then
   exit 1
 fi
 
-selection_file=$(mktemp)
-done_file=$(mktemp)
-pending_file=$(mktemp)
-pending_video_file=$(mktemp)
+ipc_dir="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+mkdir -m 700 -p "$ipc_dir"
+selection_file=$(mktemp "$ipc_dir/omarchy-menu-images.XXXXXX")
+done_file=$(mktemp "$ipc_dir/omarchy-menu-images.XXXXXX")
+pending_file=$(mktemp "$ipc_dir/omarchy-menu-images.XXXXXX")
+pending_video_file=$(mktemp "$ipc_dir/omarchy-menu-images.XXXXXX")
 rm -f "$done_file"
 trap 'rm -f "$selection_file" "$done_file" "$pending_file" "$pending_video_file"' EXIT
 
diff --git a/bin/omarchy-menu-input b/bin/omarchy-menu-input
index b61f88e332d..8a2f6114b48 100755
--- a/bin/omarchy-menu-input
+++ b/bin/omarchy-menu-input
@@ -29,8 +29,10 @@ while (( $# > 0 )); do
   shift
 done
 
-selection_file=$(mktemp)
-done_file=$(mktemp)
+ipc_dir="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+mkdir -m 700 -p "$ipc_dir"
+selection_file=$(mktemp "$ipc_dir/omarchy-menu-input.XXXXXX")
+done_file=$(mktemp "$ipc_dir/omarchy-menu-input.XXXXXX")
 rm -f "$done_file"
 trap 'rm -f "$selection_file" "$done_file"' EXIT
 
diff --git a/bin/omarchy-menu-select b/bin/omarchy-menu-select
index 1404665f30d..eafc706decf 100755
--- a/bin/omarchy-menu-select
+++ b/bin/omarchy-menu-select
@@ -67,8 +67,10 @@ if (( ${#options[@]} == 0 )); then
   exit 1
 fi
 
-selection_file=$(mktemp)
-done_file=$(mktemp)
+ipc_dir="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+mkdir -m 700 -p "$ipc_dir"
+selection_file=$(mktemp "$ipc_dir/omarchy-menu-select.XXXXXX")
+done_file=$(mktemp "$ipc_dir/omarchy-menu-select.XXXXXX")
 rm -f "$done_file"
 trap 'rm -f "$selection_file" "$done_file"' EXIT
 
diff --git a/bin/omarchy-system-lock b/bin/omarchy-system-lock
index 53e4ca5a0ef..6f5c16a4b07 100755
--- a/bin/omarchy-system-lock
+++ b/bin/omarchy-system-lock
@@ -12,11 +12,18 @@ hyprctl switchxkblayout all 0 > /dev/null 2>&1
 
 # Ensure 1password is locked. Use timeout because `1password --lock` can
 # otherwise leave a full Electron helper tree running after each lock.
+# Keep the flock out of world-writable /tmp: a held lock there used to make
+# `flock -n || exit 0` skip `--lock`. If the private lock file cannot be
+# created, still lock.
 if pgrep -x "1password" >/dev/null && omarchy-cmd-present 1password; then
   (
-    flock -n 9 || exit 0
+    lock_dir="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+    lock_file="$lock_dir/omarchy-1password-lock.lock"
+    if mkdir -m 700 -p "$lock_dir" && exec 9>"$lock_file"; then
+      flock -n 9 || exit 0
+    fi
     timeout --kill-after=1s 3s 1password --lock >/dev/null 2>&1 || true
-  ) 9>"${XDG_RUNTIME_DIR:-/tmp}/omarchy-1password-lock.lock" &
+  ) &
 fi
 
 # Avoid running screensaver when locked
diff --git a/bin/omarchy-theme-set b/bin/omarchy-theme-set
index 782b4ba7054..7a2bf7ac112 100755
--- a/bin/omarchy-theme-set
+++ b/bin/omarchy-theme-set
@@ -13,7 +13,9 @@ CURRENT_THEME_PATH="$HOME/.local/state/omarchy/current/theme"
 NEXT_THEME_PATH="$HOME/.local/state/omarchy/current/next-theme"
 CURRENT_BACKGROUND_LINK="$HOME/.local/state/omarchy/current/background"
 BACKGROUND_TRANSITION_CACHE="$HOME/.cache/omarchy/background-transitions"
-THEME_SET_LOCK="${XDG_RUNTIME_DIR:-/tmp}/omarchy-theme-set.lock"
+THEME_SET_LOCK_DIR="${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}"
+mkdir -m 700 -p "$THEME_SET_LOCK_DIR"
+THEME_SET_LOCK="$THEME_SET_LOCK_DIR/omarchy-theme-set.lock"
 USER_THEMES_PATH="$HOME/.config/omarchy/themes"
 OMARCHY_THEMES_PATH="$OMARCHY_PATH/themes"
 
diff --git a/test/shell.d/dev-link-test.sh b/test/shell.d/dev-link-test.sh
index 748b3780fbb..bb55fa72e04 100644
--- a/test/shell.d/dev-link-test.sh
+++ b/test/shell.d/dev-link-test.sh
@@ -52,8 +52,26 @@ printf 'reboot\n' >>"$OMARCHY_DEV_LINK_TEST_LOG"
 SH
 chmod +x "$stub_bin/omarchy-system-reboot"
 
+cat >"$stub_bin/realpath" <<'SH'
+#!/bin/bash
+while (( $# )); do
+  case "$1" in
+    -e|--canonicalize-existing) shift ;;
+    -*) shift ;;
+    *) break ;;
+  esac
+done
+[[ -n ${1:-} && -e $1 ]] || exit 1
+printf '%s\n' "$1"
+SH
+chmod +x "$stub_bin/realpath"
+
+runtime_dir="$test_tmp/runtime"
+mkdir -m 700 -p "$runtime_dir"
+
 run_link() {
   HOME="$test_tmp/home" \
+    XDG_RUNTIME_DIR="$runtime_dir" \
     OMARCHY_DEV_LINK_TEST_LOG="$log_file" \
     OMARCHY_DEV_LINK_TEST_CONF="$conf_file" \
     OMARCHY_DEV_LINK_TEST_SUDOERS="$sudoers_file" \
@@ -88,6 +106,18 @@ grep -Eq $'^sudo\tinstall\t-Dm440\t-o\troot\t-g\troot\t[^\t]+\t/etc/sudoers\\.d/
   fail "dev link installs the drop-in root-owned and read-only" "$(cat "$log_file")"
 pass "dev link installs the drop-in root-owned and read-only"
 
+staged_path=$(awk -F '\t' '$1 == "sudo" && $2 == "install" { print $(NF-1) }' "$log_file")
+[[ $staged_path == "$runtime_dir"/omarchy-dev-path.* ]] ||
+  fail "dev link stages sudoers under XDG_RUNTIME_DIR" "$(cat "$log_file")"
+pass "dev link stages sudoers under XDG_RUNTIME_DIR"
+
+if grep -Fq 'staged_sudoers=$(mktemp)' "$ROOT/bin/omarchy-dev-link"; then
+  fail "dev link must not mktemp sudoers in the default /tmp"
+fi
+grep -Fq '${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}' "$ROOT/bin/omarchy-dev-link" ||
+  fail "dev link falls back to a 0700 /tmp/omarchy-\$UID directory"
+pass "dev link does not stage sudoers in world-writable /tmp"
+
 visudo -cf "$sudoers_file" >/dev/null ||
   fail "dev link writes a sudoers drop-in sudo can parse" "$(<"$sudoers_file")"
 pass "dev link writes a sudoers drop-in sudo can parse"
diff --git a/test/shell.d/menu-ipc-path-test.sh b/test/shell.d/menu-ipc-path-test.sh
new file mode 100755
index 00000000000..59e0b293deb
--- /dev/null
+++ b/test/shell.d/menu-ipc-path-test.sh
@@ -0,0 +1,70 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+require_command perl
+
+tmpdir=$(mktemp -d)
+trap 'rm -rf "$tmpdir"' EXIT
+
+runtime_dir="$tmpdir/runtime"
+stub_bin="$tmpdir/bin"
+ipc_log="$tmpdir/ipc.log"
+mkdir -m 700 -p "$runtime_dir" "$stub_bin"
+
+cat >"$stub_bin/omarchy-shell" <<'SH'
+#!/bin/bash
+payload="${@: -1}"
+perl -MJSON::PP=decode_json -e '
+  my $p = decode_json($ARGV[0]);
+  my $sel = $p->{selectionFile};
+  my $done = $p->{doneFile};
+  die "missing ipc paths" unless defined $sel && defined $done;
+  if (defined $ENV{IPC_LOG}) {
+    open my $l, ">>", $ENV{IPC_LOG} or die $!;
+    print $l "$sel\n$done\n";
+    close $l;
+  }
+  open my $s, ">", $sel or die $!;
+  print $s "picked\n";
+  close $s;
+  open my $d, ">", $done or die $!;
+  close $d;
+' "$payload"
+SH
+chmod +x "$stub_bin/omarchy-shell"
+
+for cmd in omarchy-menu-select omarchy-menu-input omarchy-menu-images; do
+  if grep -E '^selection_file=\$\(mktemp\)$' "$ROOT/bin/$cmd"; then
+    fail "$cmd must not mktemp in the default /tmp"
+  fi
+  grep -Fq '${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}' "$ROOT/bin/$cmd" ||
+    fail "$cmd stages menu IPC under the runtime directory"
+done
+pass "menu helpers do not stage IPC files in world-writable /tmp"
+
+: >"$ipc_log"
+PATH="$stub_bin:$PATH" XDG_RUNTIME_DIR="$runtime_dir" IPC_LOG="$ipc_log" \
+  "$ROOT/bin/omarchy-menu-select" Prompt one >"$tmpdir/select.out"
+
+[[ $(<"$tmpdir/select.out") == picked ]] ||
+  fail "menu-select still returns the chosen row" "$(<"$tmpdir/select.out")"
+while IFS= read -r path; do
+  [[ $path == "$runtime_dir"/omarchy-menu-select.* ]] ||
+    fail "menu-select IPC path is under XDG_RUNTIME_DIR" "$path"
+done <"$ipc_log"
+pass "menu-select stages IPC under XDG_RUNTIME_DIR"
+
+: >"$ipc_log"
+PATH="$stub_bin:$PATH" XDG_RUNTIME_DIR="$runtime_dir" IPC_LOG="$ipc_log" \
+  "$ROOT/bin/omarchy-menu-input" Reminder >"$tmpdir/input.out"
+
+[[ $(<"$tmpdir/input.out") == picked ]] ||
+  fail "menu-input still returns the typed value" "$(<"$tmpdir/input.out")"
+while IFS= read -r path; do
+  [[ $path == "$runtime_dir"/omarchy-menu-input.* ]] ||
+    fail "menu-input IPC path is under XDG_RUNTIME_DIR" "$path"
+done <"$ipc_log"
+pass "menu-input stages IPC under XDG_RUNTIME_DIR"
diff --git a/test/shell.d/monitor-recovery-test.sh b/test/shell.d/monitor-recovery-test.sh
index 3401abc18da..ae6f386f937 100755
--- a/test/shell.d/monitor-recovery-test.sh
+++ b/test/shell.d/monitor-recovery-test.sh
@@ -23,6 +23,16 @@ grep -F 'flock -n 9' "$monitor_watch" >/dev/null
 grep -F 'omarchy-hyprland-monitor-clamshell' "$monitor_watch" >/dev/null
 pass "monitor watcher retries internal monitor recovery after removal"
 
+if grep -Fq '${XDG_RUNTIME_DIR:-/tmp}/omarchy-monitor-clamshell.lock' "$monitor_watch" ||
+  grep -Fq '${XDG_RUNTIME_DIR:-/tmp}/omarchy-monitor-modeless.lock' "$monitor_watch"; then
+  fail "monitor watcher flock files must not fall back to world-writable /tmp"
+fi
+grep -Fq '${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}' "$monitor_watch" ||
+  fail "monitor watcher flock falls back to a 0700 /tmp/omarchy-\$UID directory"
+grep -Fq 'mkdir -m 700 -p "$LOCK_DIR"' "$monitor_watch" ||
+  fail "monitor watcher creates the flock directory with mode 0700"
+pass "monitor watcher flock files are not in world-writable /tmp"
+
 grep -F 'monitoradded\>\>*|monitoraddedv2\>\>*)' "$monitor_watch" >/dev/null
 grep -F 'omarchy-hyprland-monitor-clamshell' "$monitor_watch" >/dev/null
 pass "monitor watcher disables the internal monitor after closed-lid external hotplug"
diff --git a/test/shell.d/system-lock-test.sh b/test/shell.d/system-lock-test.sh
index da79eac045e..1ced98ee694 100755
--- a/test/shell.d/system-lock-test.sh
+++ b/test/shell.d/system-lock-test.sh
@@ -34,3 +34,52 @@ mapfile -t shutdown < <(rg '^(pkill|timeout) ' "$call_log")
 [[ ${shutdown[2]} == "pkill -f [o]rg.omarchy.screensaver" ]] ||
   fail "system lock closes the screensaver terminal after ttfx exits" "calls: ${shutdown[*]}"
 pass "system lock waits for ttfx before closing its terminal"
+
+lock_src="$ROOT/bin/omarchy-system-lock"
+if grep -Fq '${XDG_RUNTIME_DIR:-/tmp}/omarchy-1password-lock.lock' "$lock_src"; then
+  fail "1Password flock must not fall back to world-writable /tmp"
+fi
+grep -Fq '${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}' "$lock_src" ||
+  fail "1Password flock falls back to a 0700 /tmp/omarchy-\$UID directory"
+grep -Fq 'flock -n 9 || exit 0' "$lock_src" ||
+  fail "1Password flock still dedupes an in-progress lock"
+grep -Fq 'timeout --kill-after=1s 3s 1password --lock' "$lock_src" ||
+  fail "system lock still issues 1password --lock"
+pass "1Password lock file is not in world-writable /tmp"
+
+runtime_dir="$tmpdir/runtime"
+mkdir -m 700 -p "$runtime_dir"
+: >"$call_log"
+
+cat >"$mock_bin/pgrep" <<'SH'
+#!/bin/bash
+[[ $1 == -x && $2 == 1password ]]
+SH
+cat >"$mock_bin/omarchy-cmd-present" <<'SH'
+#!/bin/bash
+[[ $1 == 1password ]]
+SH
+cat >"$mock_bin/1password" <<'SH'
+#!/bin/bash
+printf '1password %s\n' "$*" >>"$CALL_LOG"
+SH
+# Arch has util-linux flock; this suite also runs where it is not on PATH.
+cat >"$mock_bin/flock" <<'SH'
+#!/bin/bash
+exit 0
+SH
+chmod +x "$mock_bin"/*
+
+PATH="$mock_bin:$PATH" CALL_LOG="$call_log" XDG_RUNTIME_DIR="$runtime_dir" \
+  "$ROOT/bin/omarchy-system-lock"
+
+for _ in {1..40}; do
+  grep -Fq 'timeout --kill-after=1s 3s 1password --lock' "$call_log" && break
+  sleep 0.05
+done
+
+grep -Fq 'timeout --kill-after=1s 3s 1password --lock' "$call_log" ||
+  fail "system lock still calls 1password --lock when 1Password is running" "$(cat "$call_log")"
+[[ -e $runtime_dir/omarchy-1password-lock.lock ]] ||
+  fail "1Password flock is created under XDG_RUNTIME_DIR"
+pass "1Password flock lives in the runtime directory"
diff --git a/test/shell.d/theme-set-lock-test.sh b/test/shell.d/theme-set-lock-test.sh
new file mode 100755
index 00000000000..792dbf12878
--- /dev/null
+++ b/test/shell.d/theme-set-lock-test.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+theme_set="$ROOT/bin/omarchy-theme-set"
+
+if grep -Fq '${XDG_RUNTIME_DIR:-/tmp}/omarchy-theme-set.lock' "$theme_set"; then
+  fail "theme-set flock must not fall back to world-writable /tmp"
+fi
+grep -Fq '${XDG_RUNTIME_DIR:-/tmp/omarchy-$UID}' "$theme_set" ||
+  fail "theme-set flock falls back to a 0700 /tmp/omarchy-\$UID directory"
+grep -Fq 'mkdir -m 700 -p "$THEME_SET_LOCK_DIR"' "$theme_set" ||
+  fail "theme-set creates the flock directory with mode 0700"
+grep -Fq 'THEME_SET_LOCK="$THEME_SET_LOCK_DIR/omarchy-theme-set.lock"' "$theme_set" ||
+  fail "theme-set keeps the flock file name"
+pass "theme-set flock is not in world-writable /tmp"