diff --git a/src/specify_cli/workflows/_commands.py b/src/specify_cli/workflows/_commands.py
index 813ba992fb..5e40569af0 100644
--- a/src/specify_cli/workflows/_commands.py
+++ b/src/specify_cli/workflows/_commands.py
@@ -1708,6 +1708,24 @@ def workflow_list():
         console.print()
 
 
+def _cleanup_download_tmp_path(tmp_path: Path | None) -> None:
+    """Best-effort unlink of a partially-downloaded workflow temp file.
+
+    A cleanup ``OSError`` here must never replace/mask whatever error or
+    interrupt is already propagating -- warn about it and keep going.
+    """
+    if tmp_path is None:
+        return
+    try:
+        tmp_path.unlink(missing_ok=True)
+    except OSError as cleanup_exc:
+        console.print(
+            "[yellow]Warning:[/yellow] Could not remove temporary "
+            f"workflow download file: {_escape_markup(str(cleanup_exc))} "
+            f"(path: {_escape_markup(str(tmp_path))})"
+        )
+
+
 @workflow_app.command("add")
 def workflow_add(
     source: str = typer.Argument(..., help="Workflow ID, URL, or local path"),
@@ -2037,23 +2055,23 @@ def _validate_and_install_local(
                             _enforce_workflow_yaml_size(downloaded_content)
                     tmp.write(downloaded_content)
         except typer.Exit:
+            _cleanup_download_tmp_path(tmp_path)
             raise
         except Exception as exc:
-            if tmp_path is not None:
-                # A cleanup failure here must never replace/mask the
-                # original download error below with a raw, unhandled
-                # OSError -- warn about it and keep going, exactly like the
-                # later post-install finally cleanup does.
-                try:
-                    tmp_path.unlink(missing_ok=True)
-                except OSError as cleanup_exc:
-                    console.print(
-                        "[yellow]Warning:[/yellow] Could not remove temporary "
-                        f"workflow download file: {_escape_markup(str(cleanup_exc))} "
-                        f"(path: {_escape_markup(str(tmp_path))})"
-                    )
+            # A cleanup failure here must never replace/mask the
+            # original download error below with a raw, unhandled
+            # OSError -- warn about it and keep going, exactly like the
+            # later post-install finally cleanup does.
+            _cleanup_download_tmp_path(tmp_path)
             console.print(f"[red]Error:[/red] Failed to download workflow: {_escape_markup(str(exc))}")
             raise typer.Exit(1)
+        except BaseException:
+            # Covers KeyboardInterrupt and other non-Exception exits: the
+            # temp file is already created on disk (delete=False) by this
+            # point, so an interrupt during the size-limited read must still
+            # unlink it rather than leaking it to the system temp directory.
+            _cleanup_download_tmp_path(tmp_path)
+            raise
         try:
             if downloaded_archive_format is None:
                 _validate_and_install_local(
diff --git a/tests/test_workflows.py b/tests/test_workflows.py
index afd70adecf..2242daad97 100644
--- a/tests/test_workflows.py
+++ b/tests/test_workflows.py
@@ -12343,6 +12343,46 @@ def test_add_from_url_oversized_streamed_body_leaves_no_temp_file(
         leaked = list(scratch_tmp.glob("*.yml"))
         assert leaked == [], f"leaked temp files: {leaked}"
 
+    def test_add_from_url_interrupt_during_read_leaves_no_temp_file(
+        self, project_dir, monkeypatch, tmp_path
+    ):
+        """A KeyboardInterrupt while streaming the response body must still
+        unlink the already-created (delete=False) temp file. Unlike a
+        download ``ValueError``, ``KeyboardInterrupt`` is a ``BaseException``
+        and is not caught by ``except Exception`` -- only a ``BaseException``
+        handler around the temp-file lifetime can clean it up."""
+        import tempfile as tempfile_mod
+        from unittest.mock import patch
+        from typer.testing import CliRunner
+        from specify_cli import app
+        from specify_cli.workflows import _commands as wf_commands
+
+        monkeypatch.chdir(project_dir)
+        scratch_tmp = tmp_path / "scratch-tmp"
+        scratch_tmp.mkdir()
+        monkeypatch.setattr(tempfile_mod, "tempdir", str(scratch_tmp))
+
+        def _boom(*args, **kwargs):
+            raise KeyboardInterrupt()
+
+        monkeypatch.setattr(wf_commands, "_read_response_within_limit", _boom)
+        body = b"id: align-wf\n"
+        runner = CliRunner()
+        with patch(
+            "specify_cli.authentication.http.open_url",
+            side_effect=lambda url, timeout=None, extra_headers=None, redirect_validator=None: self._FakeResponse(
+                body, url
+            ),
+        ):
+            result = runner.invoke(
+                app,
+                ["workflow", "add", "align-wf", "--from", "https://example.com/workflow.yml"],
+                input="y\n",
+            )
+        assert result.exit_code != 0
+        leaked = list(scratch_tmp.glob("*.yml"))
+        assert leaked == [], f"leaked temp files: {leaked}"
+
     def test_add_from_url_oversized_content_length_leaves_no_temp_file(
         self, project_dir, monkeypatch, tmp_path
     ):