diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9e94b5e..461f8e2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Hermes Web UI -- Changelog
 
+## [v0.50.71] — 2026-04-16
+
+### Fixed
+- **Docker: `HERMES_WEBUI_DEFAULT_WORKSPACE` was silently overridden by `settings.json`** — the startup block in `api/config.py` unconditionally restored the persisted `default_workspace`, so any container that had previously written `settings.json` would shadow the env var on the next start. The env var now wins when explicitly set, matching the documented priority order. (Closes #609, PR #610)
+- **Docker: workspace trust validation rejected subdirectories of `DEFAULT_WORKSPACE`** — `resolve_trusted_workspace()` only trusted paths under `Path.home()` or in the saved list; subpaths of a Docker volume mount like `/data/workspace/myproject` failed with "outside the user home directory". Added a third trust condition for paths under the boot-time `DEFAULT_WORKSPACE`, which was already validated at startup. (Closes #609, PR #610)
+
 ## [v0.50.70] — 2026-04-16
 
 ### Changed
diff --git a/api/config.py b/api/config.py
index c4668da..c82fcf7 100644
--- a/api/config.py
+++ b/api/config.py
@@ -1311,13 +1311,18 @@ def save_settings(settings: dict) -> dict:
 
 
 # Apply saved settings on startup (override env-derived defaults)
+# Exception: if HERMES_WEBUI_DEFAULT_WORKSPACE is explicitly set in the
+# environment, it wins over whatever settings.json has stored.  Persisted
+# config must never shadow an explicit env-var override (Docker deployments
+# rely on this — otherwise deleting settings.json is the only escape).
 _startup_settings = load_settings()
 if SETTINGS_FILE.exists():
     if _startup_settings.get("default_model"):
         DEFAULT_MODEL = _startup_settings["default_model"]
-    DEFAULT_WORKSPACE = resolve_default_workspace(
-        _startup_settings.get("default_workspace")
-    )
+    if not os.getenv("HERMES_WEBUI_DEFAULT_WORKSPACE"):
+        DEFAULT_WORKSPACE = resolve_default_workspace(
+            _startup_settings.get("default_workspace")
+        )
     if _startup_settings.get("default_workspace") != str(DEFAULT_WORKSPACE):
         _startup_settings["default_workspace"] = str(DEFAULT_WORKSPACE)
         try:
diff --git a/api/workspace.py b/api/workspace.py
index 070b0c8..dddae29 100644
--- a/api/workspace.py
+++ b/api/workspace.py
@@ -283,9 +283,22 @@ def resolve_trusted_workspace(path: str | Path | None = None) -> Path:
     except Exception:
         pass
 
+    # (C) Trusted if it is equal to or under the boot-time DEFAULT_WORKSPACE.
+    #     In Docker deployments HERMES_WEBUI_DEFAULT_WORKSPACE is often set to a
+    #     volume mount outside the user's home (e.g. /data/workspace).  That path
+    #     was already validated at server startup, so any sub-path of it is safe
+    #     without requiring the user to add it to the workspace list manually.
+    try:
+        boot_default = Path(_BOOT_DEFAULT_WORKSPACE).expanduser().resolve()
+        candidate.relative_to(boot_default)
+        return candidate
+    except ValueError:
+        pass
+
     raise ValueError(
-        f"Path is outside the user home directory and not in the saved workspace "
-        f"list: {candidate}. Add it via Settings → Workspaces first."
+        f"Path is outside the user home directory, not in the saved workspace "
+        f"list, and not under the default workspace: {candidate}. "
+        f"Add it via Settings → Workspaces first."
     )
 
 
diff --git a/static/index.html b/static/index.html
index e87bc6c..9916ce0 100644
--- a/static/index.html
+++ b/static/index.html
@@ -558,7 +558,7 @@
                 <div class="settings-section-title">System</div>
                 <div class="settings-section-meta">Instance version and access controls.</div>
               </div>
-              <span class="settings-version-badge">v0.50.70</span>
+              <span class="settings-version-badge">v0.50.71</span>
             </div>
             <div class="settings-field" style="border-top:1px solid var(--border);padding-top:12px;margin-top:8px">
               <label for="settingsPassword" data-i18n="settings_label_password">Access Password</label>
diff --git a/tests/test_default_workspace_fallback.py b/tests/test_default_workspace_fallback.py
index 2bb3329..0934be0 100644
--- a/tests/test_default_workspace_fallback.py
+++ b/tests/test_default_workspace_fallback.py
@@ -101,3 +101,48 @@ def test_ensure_workspace_dir_returns_false_for_unwritable_path(monkeypatch, tmp
         assert result is False
     finally:
         parent.chmod(stat.S_IRWXU)
+
+
+def test_env_var_wins_over_settings_json_on_startup(monkeypatch, tmp_path):
+    """HERMES_WEBUI_DEFAULT_WORKSPACE must not be overridden by settings.json at startup.
+
+    Regression for GitHub issue #609: Docker deployments set the env var to a
+    volume mount, but settings.json from a previous container run used to
+    silently win, reverting the files panel to the old path.
+    """
+    import json as _json
+    import os as _os
+
+    env_ws = tmp_path / "env_workspace"
+    env_ws.mkdir()
+    settings_ws = tmp_path / "settings_workspace"
+    settings_ws.mkdir()
+    state_dir = tmp_path / "state"
+    state_dir.mkdir()
+    settings_file = state_dir / "settings.json"
+    settings_file.write_text(
+        _json.dumps({"default_workspace": str(settings_ws)}), encoding="utf-8"
+    )
+
+    monkeypatch.setattr(config, "HOME", tmp_path)
+    monkeypatch.setattr(config, "STATE_DIR", state_dir)
+    monkeypatch.setattr(config, "SETTINGS_FILE", settings_file)
+    # Simulate DEFAULT_WORKSPACE already set correctly from env var at import time
+    monkeypatch.setattr(config, "DEFAULT_WORKSPACE", env_ws.resolve())
+    monkeypatch.setenv("HERMES_WEBUI_DEFAULT_WORKSPACE", str(env_ws))
+
+    # Execute the patched startup block logic inline — env var present → skip override
+    current_ws = config.DEFAULT_WORKSPACE
+    startup_settings = config.load_settings()
+    if not _os.getenv("HERMES_WEBUI_DEFAULT_WORKSPACE"):
+        # This branch must be skipped because env var is set
+        current_ws = config.resolve_default_workspace(
+            startup_settings.get("default_workspace")
+        )
+
+    # env var was set → the if block was skipped → env path wins over settings.json
+    assert current_ws == env_ws.resolve(), (
+        f"Expected {env_ws.resolve()}, got {current_ws}. "
+        "settings.json must not override HERMES_WEBUI_DEFAULT_WORKSPACE."
+    )
+
diff --git a/tests/test_issue609.py b/tests/test_issue609.py
new file mode 100644
index 0000000..5716e3f
--- /dev/null
+++ b/tests/test_issue609.py
@@ -0,0 +1,107 @@
+"""
+Tests for GitHub issue #609 — Docker workspace path trust and env-var priority.
+
+Two independent bugs were fixed:
+
+  1. HERMES_WEBUI_DEFAULT_WORKSPACE env var was silently overridden by
+     settings.json at server startup.  The env var must always win.
+
+  2. resolve_trusted_workspace() rejected paths that are children of
+     DEFAULT_WORKSPACE (e.g. /data/workspace/project) when the default is a
+     Docker volume mount outside the user's home directory.  Any path under
+     the boot-time default should be trusted automatically.
+"""
+from pathlib import Path
+
+import pytest
+
+from api.workspace import resolve_trusted_workspace
+
+
+# ── Fix 2: trust paths under DEFAULT_WORKSPACE ───────────────────────────────
+
+def test_subdir_of_boot_default_is_trusted(monkeypatch, tmp_path):
+    """A subdirectory of BOOT_DEFAULT_WORKSPACE must be trusted without being in
+    the saved workspace list and without being under the user's home directory.
+
+    This is the core Docker case: DEFAULT_WORKSPACE=/data/workspace, and the
+    user tries to open /data/workspace/myproject — should NOT raise ValueError.
+    """
+    import api.workspace as ws_mod
+
+    boot_default = tmp_path / "data" / "workspace"
+    boot_default.mkdir(parents=True)
+    sub = boot_default / "myproject"
+    sub.mkdir()
+
+    monkeypatch.setattr(ws_mod, "_BOOT_DEFAULT_WORKSPACE", str(boot_default))
+
+    # Should not raise — sub is under the boot default
+    result = resolve_trusted_workspace(str(sub))
+    assert result == sub.resolve()
+
+
+def test_boot_default_itself_is_trusted(monkeypatch, tmp_path):
+    """The DEFAULT_WORKSPACE path itself must also be trusted (not only subdirs)."""
+    import api.workspace as ws_mod
+
+    boot_default = tmp_path / "data" / "workspace"
+    boot_default.mkdir(parents=True)
+
+    monkeypatch.setattr(ws_mod, "_BOOT_DEFAULT_WORKSPACE", str(boot_default))
+
+    result = resolve_trusted_workspace(str(boot_default))
+    assert result == boot_default.resolve()
+
+
+def test_path_outside_boot_default_and_home_is_rejected(monkeypatch, tmp_path):
+    """A path that is not under home, not in the saved list, and not under
+    DEFAULT_WORKSPACE must still be rejected."""
+    import api.workspace as ws_mod
+
+    boot_default = tmp_path / "data" / "workspace"
+    boot_default.mkdir(parents=True)
+    outside = tmp_path / "other_mount" / "secret"
+    outside.mkdir(parents=True)
+
+    monkeypatch.setattr(ws_mod, "_BOOT_DEFAULT_WORKSPACE", str(boot_default))
+
+    with pytest.raises(ValueError, match="outside the user home"):
+        resolve_trusted_workspace(str(outside))
+
+
+def test_none_path_returns_boot_default(monkeypatch, tmp_path):
+    """resolve_trusted_workspace(None) always returns the boot default unchanged."""
+    import api.workspace as ws_mod
+
+    boot_default = tmp_path / "data" / "workspace"
+    boot_default.mkdir(parents=True)
+
+    monkeypatch.setattr(ws_mod, "_BOOT_DEFAULT_WORKSPACE", str(boot_default))
+
+    result = resolve_trusted_workspace(None)
+    assert result == boot_default.resolve()
+
+
+def test_path_traversal_via_dotdot_does_not_escape_boot_default(monkeypatch, tmp_path):
+    """A path that uses `..` to escape DEFAULT_WORKSPACE must not be trusted by (C).
+
+    `Path.resolve()` collapses `..` before the `relative_to(boot_default)` check
+    runs, so `/data/workspace/../etc` resolves to `/etc` and is rejected (it's
+    also caught earlier by the system-roots block, but this test pins the
+    behavior in case the order of conditions ever changes).
+    """
+    import api.workspace as ws_mod
+
+    boot_default = tmp_path / "data" / "workspace"
+    boot_default.mkdir(parents=True)
+    sibling = tmp_path / "data" / "private"
+    sibling.mkdir(parents=True)
+
+    monkeypatch.setattr(ws_mod, "_BOOT_DEFAULT_WORKSPACE", str(boot_default))
+
+    # `boot_default/../private` resolves to `tmp_path/data/private`, which is
+    # NOT a child of boot_default and not under home — must reject.
+    escape = boot_default / ".." / "private"
+    with pytest.raises(ValueError, match="outside the user home"):
+        resolve_trusted_workspace(str(escape))