refactor(session): simplify traversal guard to a helper + logger, harden non-leading separators

Follow-up to the salvaged #9560 fix:
- Replace the _TRAVERSAL_RE regex with an explicit _is_path_unsafe() helper
  (drops the now-unused `import re`); catches a path separator ANYWHERE,
  not just leading, so a non-leading Windows backslash can't slip through.
- Switch the per-entry skip in _ensure_loaded_locked from print() to
  logger.warning to match the module's logging conventions.
- Add AUTHOR_MAP entry for the contributor.
- Add regression tests for the non-leading-separator case.

gateway/session.py

@@ -12,7 +12,6 @@ import hashlib
 import logging
 import os
 import json
-import re
 import threading
 import uuid
 from pathlib import Path
@@ -67,10 +66,27 @@ from .whatsapp_identity import (
 )
 from utils import atomic_replace
 
-# Matches any value that could escape the sessions directory as a file path.
-# Covers: directory traversal (..),  Unix/Windows absolute paths (/  \),
-# and Windows drive-letter paths (C:/ D:\\ etc.).
-_TRAVERSAL_RE = re.compile(r'\.\.|^[/\\]|^[A-Za-z]:')
+# Session keys/ids flow into filesystem paths downstream (e.g.
+# ``sessions_dir / f"{session_id}.json"`` in hermes_state, request-dump
+# filenames in agent_runtime_helpers). Any value that could escape the
+# sessions directory as a path must be rejected at the entry boundary.
+# Rejects: parent traversal (``..``), a path separator anywhere (``/`` or
+# ``\``, so a non-leading Windows separator can't slip through), and a
+# leading Windows drive letter (``C:``). Legitimate session keys are
+# colon-delimited multi-segment ids (``agent:main:<platform>:...``) and
+# never contain these, so there are no false positives in practice.
+def _is_path_unsafe(value: object) -> bool:
+    """Return True if ``value`` could traverse outside the sessions dir."""
+    if not value:
+        return False
+    s = str(value)
+    if ".." in s or "/" in s or "\\" in s:
+        return True
+    # Leading Windows drive path, e.g. "C:\..." or "d:/...". A bare "x:"
+    # with no following separator isn't a usable absolute path, and the
+    # separator forms are already caught above — but keep an explicit guard
+    # for the drive-letter prefix in case a separator was normalized away.
+    return len(s) >= 2 and s[0].isalpha() and s[1] == ":"
 
 
 @dataclass
@@ -584,7 +600,7 @@ class SessionEntry:
 
         # Validate path-sensitive fields to prevent directory traversal (CWE-22)
         for _field, _val in (("session_key", session_key), ("session_id", session_id)):
-            if _val and _TRAVERSAL_RE.search(str(_val)):
+            if _is_path_unsafe(_val):
                 raise ValueError(
                     f"Invalid {_field}: potential directory traversal detected"
                 )
@@ -796,7 +812,7 @@ class SessionStore:
                     try:
                         self._entries[key] = SessionEntry.from_dict(entry_data)
                     except (ValueError, KeyError) as e:
-                        print(f"[gateway] Warning: Skipping invalid session entry {key!r}: {e}")
+                        logger.warning("Skipping invalid session entry %r: %s", key, e)
             except Exception as e:
                 print(f"[gateway] Warning: Failed to load sessions: {e}")
 

scripts/release.py

@@ -45,6 +45,7 @@ ACP_REGISTRY_MANIFEST = REPO_ROOT / "acp_registry" / "agent.json"
 
 # Auto-extracted from noreply emails + manual overrides
 AUTHOR_MAP = {
+    "mediratta01.pally@gmail.com": "orbisai0security",  # PR #9560 salvage (session.py path-traversal guard, V-009)
     "panghuer023@users.noreply.github.com": "panghuer023",  # PR #37994 salvage (interrupt unblocks pending gateway approval; #8697)
     "w.a.t.s.o.n.mk10@gmail.com": "natehale",  # PR #48678 salvage (typing indicator lingers after final reply)
     "0x0sec@gmail.com": "kn8-codes",  # PR #48422 salvage (rich messages opt-in default off)

tests/gateway/test_session.py

@@ -1095,6 +1095,15 @@ class TestSessionEntryFromDictTraversalValidation:
         with pytest.raises(ValueError, match="session_id"):
             SessionEntry.from_dict(self._entry(session_id="D:\\path\\to\\file"))
 
+    def test_session_id_non_leading_separator_raises(self):
+        """A path separator anywhere — not just leading — must be rejected,
+        since a non-leading backslash is still a Windows traversal vector."""
+        from gateway.session import SessionEntry
+        with pytest.raises(ValueError, match="session_id"):
+            SessionEntry.from_dict(self._entry(session_id="good\\..\\bad"))
+        with pytest.raises(ValueError, match="session_key"):
+            SessionEntry.from_dict(self._entry(session_key="agent:main:good/sub"))
+
 
 class TestEnsureLoadedSkipsInvalidEntries:
     """Regression: one bad sessions.json entry must not block valid entries from loading."""