guard-hook-unknown-session-id-cross-session-bypass

If CLAUDE_SESSION_ID is missing and the guard hook falls back to ‘unknown’ as a session ID, any session that invokes setup-curator creates a shared /tmp/.setup-curator-invoked-unknown marker that bypasses the write guard for all subsequent sessions. Fix: when session_id is missing, treat it as no marker and always warn; refuse to create the shared flag.

Related

• self-evolving-is-model-discipline-not-hook-enforced
• setup-curator-three-layer-self-maintenance-architecture
• stop-hook-actively-blocks-on-missing-verification-steps
• 2026-04-04-oracle-001-self-architecture-analysis
• hook-script-executable-permission-silent-failure
• setup-curator-three-layer-enforcement-architecture
• session-id-isolation-bug-in-guard-marker-hooks