diff --git a/install.sh b/install.sh
index 3bc2ff4c88..f7d4baa19c 100755
--- a/install.sh
+++ b/install.sh
@@ -655,6 +655,15 @@ _apt_distro_description() {
     )
 }
 
+# ── Helper: can the controlling terminal actually be opened for reading? ──
+# `test -r` only checks permission bits, which look fine in containers and
+# systemd units where open() then fails with ENXIO. Probe with a real open.
+# The subshell is required: in dash a failed redirection on the special
+# builtin `:` exits the whole script.
+_can_read_tty() {
+    ( : </dev/tty ) >/dev/null 2>&1
+}
+
 # ── Helper: install packages via apt, escalating to sudo only if needed ──
 # Usage: _smart_apt_install pkg1 pkg2 pkg3 ...
 _smart_apt_install() {
@@ -695,24 +704,51 @@ _smart_apt_install() {
         echo "    from your distro's official repositories (not a third-party tarball)."
         echo "    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
         echo ""
-        printf "    Accept? [Y/n] "
-        if [ -r /dev/tty ]; then
-            read -r REPLY </dev/tty || REPLY="y"
+        if _can_read_tty; then
+            printf "    Accept? [Y/n] "
+            # The device opened, so a failed read is EOF, not consent: decline,
+            # as the autostart prompt below does. Enter is still yes (a
+            # successful read of an empty line).
+            read -r REPLY </dev/tty || REPLY="n"
+            case "$REPLY" in
+                [nN]*)
+                    echo ""
+                    echo "    Please install these packages first, then re-run Unsloth Studio setup:"
+                    echo "    sudo apt-get update -y && sudo apt-get install -y $_STILL_MISSING"
+                    exit 1
+                    ;;
+            esac
+            sudo apt-get update -y </dev/null
+            sudo apt-get install -y $_STILL_MISSING </dev/null
         else
-            REPLY="y"
-        fi
-        case "$REPLY" in
-            [nN]*)
+            # Nobody can answer a prompt or type a password here. -n makes sudo
+            # refuse rather than prompt into a closed stdin, which is how #7307
+            # died. Probe with the real commands: `sudo -l` answers whether they
+            # are *authorized*, not whether running them needs authentication.
+            # -k ignores any cached timestamp, so only a real NOPASSWD rule gets
+            # through, not someone's sudo in another shell minutes ago. Per
+            # sudo(8), -k alongside a command ignores the cached credentials and
+            # "will not update" them, so other sessions keep theirs.
+            echo "    No terminal to confirm on; trying passwordless sudo."
+            if sudo -n -k apt-get update -y </dev/null &&
+                sudo -n -k apt-get install -y $_STILL_MISSING </dev/null; then
+                echo "    Installed with passwordless sudo."
+            else
                 echo ""
-                echo "    Please install these packages first, then re-run Unsloth Studio setup:"
+                echo "    Could not install these packages: $_STILL_MISSING"
+                echo "    Detected ${_ad_desc}."
+                # Either sudo refused, or apt failed on a bad repo, dpkg lock or
+                # network outage. sudo exits 1 on an auth/config problem and
+                # when the command cannot be executed, but otherwise passes the
+                # command's own status through, so state both causes.
+                echo "    Either sudo needs a password here, or apt-get itself"
+                echo "    failed; see the error above. With no terminal to"
+                echo "    authenticate on, this cannot be done unattended."
+                echo "    Please install them first, then re-run Unsloth Studio setup:"
                 echo "    sudo apt-get update -y && sudo apt-get install -y $_STILL_MISSING"
                 exit 1
-                ;;
-            *)
-                sudo apt-get update -y </dev/null
-                sudo apt-get install -y $_STILL_MISSING </dev/null
-                ;;
-        esac
+            fi
+        fi
     else
         echo ""
         echo "    sudo is not available on this system."
diff --git a/tests/sh/test_apt_distro_prompt.sh b/tests/sh/test_apt_distro_prompt.sh
index 19601b0065..6c3d08198f 100755
--- a/tests/sh/test_apt_distro_prompt.sh
+++ b/tests/sh/test_apt_distro_prompt.sh
@@ -89,6 +89,172 @@ assert_contains "mentions apt-get" "$_smart" 'sudo apt-get'
 assert_contains "mentions official repos" "$_smart" "official repositories"
 assert_contains "rejects tarball worry" "$_smart" "not a third-party tarball"
 
+# ── No-TTY sudo escalation (#7307 Problem 7) ────────────────────────
+# The old code assumed consent when /dev/tty was unreadable, then ran sudo with
+# stdin closed, so a password-requiring host died on a raw sudo error. Drive the
+# real function with /dev/tty rewritten to a fixture, the same trick used for
+# /etc/os-release above, so every TTY state is reachable hermetically.
+echo "=== _smart_apt_install no-TTY escalation ==="
+
+# Closest portable stand-in for the /dev/tty inside containers and systemd
+# units: the mode bits satisfy `test -r`, but open() fails with ENXIO. Callers
+# must verify the shape before relying on it.
+make_unopenable() {
+    python3 -c 'import socket,sys; socket.socket(socket.AF_UNIX).bind(sys.argv[1])' \
+        "$1" 2>/dev/null
+}
+
+# $1 tty:  "tty" | "notty" | "unopenable"
+# $2 sudo: "nopasswd" | "needspasswd" | "aptneedspasswd" | "cached" | "absent"
+run_smart() {
+    _tty_mode="$1"; _sudo_mode="$2"
+    _d=$(mktemp -d -p "$_TMP_ROOT")
+    case "$_tty_mode" in
+        tty)        printf 'y\n' > "$_d/tty" ;;
+        # Opens fine but reads EOF straight away (drained/half-closed
+        # terminal): openable is not the same as answerable.
+        eof)        : > "$_d/tty" ;;
+        unopenable) make_unopenable "$_d/tty" ;;
+    esac
+
+    _f=$(mktemp -p "$_TMP_ROOT")
+    sed -n -e '/^_can_read_tty()/,/^}/p' \
+           -e '/^_smart_apt_install()/,/^}/p' "$INSTALL_SH" \
+        | sed -e "s#/dev/tty#$_d/tty#g" > "$_f"
+
+    (
+        TAURI_MODE=false
+        _apt_distro_description() { echo "TestOS 1.0 (debian-like)"; }
+        _is_pkg_installed() { return 1; }          # nothing ever installs
+        apt-get() { return 1; }                    # unprivileged attempt fails
+        command() {
+            if [ "$1" = -v ] && [ "$2" = sudo ]; then
+                [ "$_sudo_mode" != absent ]; return $?
+            fi
+            builtin command "$@"
+        }
+        # Models real sudo: -n refuses (exit 1, nothing runs) when a password
+        # would be needed. -k ignores any cached timestamp for this invocation
+        # (sudo(8)), so only a real NOPASSWD rule counts as passwordless.
+        sudo() {
+            _noninteractive=false
+            _ignore_cache=false
+            while :; do
+                case "$1" in
+                    -n) _noninteractive=true; shift ;;
+                    -k) _ignore_cache=true; shift ;;
+                    *)  break ;;
+                esac
+            done
+            if [ "$_noninteractive" = true ]; then
+                case "$_sudo_mode" in
+                    nopasswd) ;;
+                    # A valid timestamp from an earlier, unrelated sudo. Without
+                    # -k this looks passwordless; with -k it must not.
+                    cached) [ "$_ignore_cache" = true ] && return 1 ;;
+                    # Authorized for everything, NOPASSWD only on trivial
+                    # commands: `sudo -l` says yes while execution still needs
+                    # a password. Authorization is not the question to ask.
+                    aptneedspasswd)
+                        case " $* " in
+                            *" apt-get "*) return 1 ;;
+                        esac
+                        ;;
+                    *) return 1 ;;
+                esac
+            fi
+            echo "SUDO_RAN: $*"
+        }
+        # shellcheck disable=SC1090
+        . "$_f"
+        _smart_apt_install cmake 2>&1
+        echo "EXIT:$?"
+    ) || true
+}
+
+_out=$(run_smart notty needspasswd)
+assert_contains "no tty + password sudo: says it cannot run unattended" \
+    "$_out" "cannot be done unattended"
+assert_contains "no tty + password sudo: gives the manual command" \
+    "$_out" "sudo apt-get update -y && sudo apt-get install -y cmake"
+assert_contains "no tty + password sudo: names the distro" \
+    "$_out" "TestOS 1.0 (debian-like)"
+case "$_out" in
+    *SUDO_RAN*) echo "  FAIL: no tty + password sudo must not run apt-get as root"; FAIL=$((FAIL + 1)) ;;
+    *) echo "  PASS: no tty + password sudo runs nothing as root"; PASS=$((PASS + 1)) ;;
+esac
+case "$_out" in
+    *"Accept? [Y/n]"*) echo "  FAIL: must not print an unanswerable prompt"; FAIL=$((FAIL + 1)) ;;
+    *) echo "  PASS: no dangling Accept? prompt without a tty"; PASS=$((PASS + 1)) ;;
+esac
+
+# Passwordless sudo is the one case where unattended escalation is legitimate.
+_out=$(run_smart notty nopasswd)
+assert_contains "no tty + passwordless sudo: still installs" "$_out" "SUDO_RAN: apt-get install -y cmake"
+assert_contains "no tty + passwordless sudo: says why it proceeded" \
+    "$_out" "passwordless sudo"
+
+# A readable tty must behave exactly as before: prompt, then honour the answer.
+_out=$(run_smart tty needspasswd)
+assert_contains "tty present: still prompts" "$_out" "Accept? [Y/n]"
+assert_contains "tty present: accepts and installs" "$_out" "SUDO_RAN: apt-get install -y cmake"
+
+# No sudo at all keeps its own message.
+_out=$(run_smart notty absent)
+assert_contains "no sudo binary: unchanged message" "$_out" "sudo is not available on this system"
+
+# A /dev/tty that passes `test -r` but cannot be opened counts as no tty.
+# Only assert where the platform can actually produce that shape.
+_probe=$(mktemp -d -p "$_TMP_ROOT")
+if make_unopenable "$_probe/tty" && [ -r "$_probe/tty" ] && ! ( : <"$_probe/tty" ) 2>/dev/null; then
+    _out=$(run_smart unopenable needspasswd)
+    assert_contains "unopenable tty: treated as no tty" "$_out" "cannot be done unattended"
+    case "$_out" in
+        *"Accept? [Y/n]"*) echo "  FAIL: unopenable tty must not print a prompt"; FAIL=$((FAIL + 1)) ;;
+        *) echo "  PASS: unopenable tty prints no prompt"; PASS=$((PASS + 1)) ;;
+    esac
+else
+    echo "  SKIP: this platform cannot fake a readable-but-unopenable /dev/tty"
+fi
+
+# A tty that opens but yields EOF must decline: a failed read is nobody
+# answering, and calling that "yes" escalates through the branch that does
+# have a terminal.
+_out=$(run_smart eof needspasswd)
+assert_contains "eof tty: declines instead of escalating" \
+    "$_out" "Please install these packages first"
+case "$_out" in
+    *SUDO_RAN*) echo "  FAIL: eof tty must not escalate"; FAIL=$((FAIL + 1)) ;;
+    *) echo "  PASS: eof tty runs nothing as root"; PASS=$((PASS + 1)) ;;
+esac
+
+# A cached timestamp from an earlier, unrelated sudo must not count as
+# passwordless: nobody answered this run's prompt and the apt-get rule still
+# carries PASSWD. Asserts the -k is present and effective.
+_out=$(run_smart notty cached)
+assert_contains "cached credentials: says it cannot run unattended" \
+    "$_out" "cannot be done unattended"
+case "$_out" in
+    *SUDO_RAN*) echo "  FAIL: a cached timestamp must not authorise unattended install"; FAIL=$((FAIL + 1)) ;;
+    *) echo "  PASS: cached credentials run nothing as root"; PASS=$((PASS + 1)) ;;
+esac
+
+# The failure message must not blame a password when apt itself failed: sudo
+# passes the command's own exit status through when the command runs.
+assert_contains "failure message does not blame a password exclusively" \
+    "$_out" "or apt-get itself"
+
+# Authorized for apt-get but not NOPASSWD on it. Both `sudo -n true` and
+# `sudo -n -l -- apt-get ...` read this as unattended, since list mode answers
+# authorization, not authentication. Only running it with -n is truthful.
+_out=$(run_smart notty aptneedspasswd)
+assert_contains "apt-get needs a password: says it cannot run unattended" \
+    "$_out" "cannot be done unattended"
+case "$_out" in
+    *SUDO_RAN*) echo "  FAIL: apt-get needing a password must not run as root"; FAIL=$((FAIL + 1)) ;;
+    *) echo "  PASS: apt-get needing a password runs nothing as root"; PASS=$((PASS + 1)) ;;
+esac
+
 echo ""
 echo "Results: $PASS passed, $FAIL failed"
 [ "$FAIL" -eq 0 ]