CVE-2026-79311

webpy web.py 0.76 is vulnerable to Insufficient Session Expiration. The application's session management relies on periodic cleanup to expire sessions instead of checking the last-access time when a session is loaded. As a result, an expired session whose record has not yet been cleaned up can still be replayed and used, allowing an attacker holding a previously valid session cookie to continue accessing protected resources after the configured idle timeout.

webpy web.py 0.76 is vulnerable to server-side template injection (SSTI). When an application precompiles templates from a directory the attacker can write to and later renders them through the precompiled template loader, the sandbox is bypassed, allowing arbitrary Python code execution and OS command execution on the server.

webpy web.py 0.76 is vulnerable to Session Fixation. The Session._load() component reads session_id directly from the request cookie and loads that session from the store, and _save() writes back under the same session_id; there is no rotation after authentication, so a fixed session_id keeps the authenticated state.