Highlights
Denial of Service: 16 prior fixes. Scrutinize any change in this area.
cherrypy/lib/sessions.py: most-fixed (12 issues). Treat as high-risk during review.
17 high-severity fixes in this history; regressions here are high-impact.
Recurring patterns
The bug types that recur here, drawn from past fixes, not open vulnerabilities.
Denial of Service: Unhandled exceptions (such as TLS or connection errors) within the worker thread loop can cause threads to silently terminate, leading to server-wide threadpool exhaustion and complete Denial of Service.
Path Traversal: File-based session implementations using standard directory joining are vulnerable to path traversal if the session ID is not strictly canonicalized against the storage root directory, potentially exposing local files.
Session Fixation: Failing to regenerate session IDs when loading non-existent sessions or after a user authenticates allows attackers to orchestrate session fixation and hijacking attacks.