diff --git a/backend/cortex_backend/execution/artifact_boundary.py b/backend/cortex_backend/execution/artifact_boundary.py
index e994380..3b0b5db 100644
--- a/backend/cortex_backend/execution/artifact_boundary.py
+++ b/backend/cortex_backend/execution/artifact_boundary.py
@@ -354,7 +354,15 @@ def _publish_bytes(
                 mime_type=mime_type,
                 retention_seconds=retention_seconds,
             )
-        except ExecutionRepositoryError:
+        except (ExecutionRepositoryError, OSError):
+            # OSError as well, because publish_artifact re-raises it: its own
+            # handler removes the partial files and then `raise`s the original,
+            # so a full disk, a permission error or an antivirus lock arrives
+            # here unwrapped. Without this the exception escaped the boundary
+            # entirely -- the caller's `except ArtifactBoundaryError` missed
+            # it, so the staging job was never failed and stayed non-terminal
+            # for good, and the route answered 500 instead of a stable code.
+            # publish_outputs below already treats both the same way.
             raise ArtifactBoundaryError("artifact_publish_failed") from None
 
     def stage_bytes(
diff --git a/tests/test_attachment_staging.py b/tests/test_attachment_staging.py
index eb5d802..71ed611 100644
--- a/tests/test_attachment_staging.py
+++ b/tests/test_attachment_staging.py
@@ -128,3 +128,35 @@ def test_stage_bytes_duplicate_terminal_result_is_revalidated(tmp_path: Path):
     with pytest.raises(AttachmentStagingError) as error:
         service.stage(owner=OWNER, request_id="attach-integrity", content=_image_bytes())
     assert error.value.code in {"attachment_artifact_unavailable", "attachment_artifact_invalid"}
+
+
+def test_a_disk_failure_fails_the_job_instead_of_escaping(tmp_path: Path, monkeypatch):
+    """A full disk must produce a stable code and a terminal job.
+
+    `publish_artifact` removes its partial files and then re-raises the
+    original exception, so an OSError -- a full disk, a permission error, an
+    antivirus lock -- reached `_publish_bytes` unwrapped. That method caught
+    only `ExecutionRepositoryError`, so the exception escaped the boundary
+    entirely: the caller's `except ArtifactBoundaryError` missed it, `_fail`
+    never ran, the job stayed non-terminal for the rest of the installation's
+    life, and the route answered HTTP 500 rather than a stable code.
+
+    `publish_outputs` in the same class already treats both the same way.
+    """
+    repository, service = _service(tmp_path)
+
+    def full_disk(*args, **kwargs):
+        raise OSError(28, "No space left on device")
+
+    monkeypatch.setattr(ExecutionRepository, "publish_artifact", full_disk)
+
+    with pytest.raises(AttachmentStagingError):
+        service.stage(owner=OWNER, request_id="attach-disk-full", content=_image_bytes())
+
+    with repository.connect() as connection:
+        statuses = [
+            str(row["status"])
+            for row in connection.execute("SELECT status FROM execution_jobs").fetchall()
+        ]
+
+    assert statuses == ["failed"], "the staging job was left non-terminal"