Openclaw cli: OpenClaw has an arbitrary transcript path file write via gateway sessionFile (CVE-2026-28459)

In OpenClaw versions before 2026.2.12, the gateway component improperly handled the 'sessionFile' parameter, allowing an authenticated client to specify an arbitrary path for session transcript files. This lack of path containment checks permitted writing session transcript data outside the designated sessions directory. Depending on filesystem permissions, this could lead to arbitrary file creation and repeated appends, resulting in configuration corruption or denial of service. The vulnerability does not directly enable remote code execution. The issue was resolved by adding containment checks in the resolveSessionFilePath function, restricting transcript file writes to the sessions directory. The fix is included starting from OpenClaw version 2026.2.12, with recommendation to use 2026.2.13 or later.

An authenticated gateway client can influence where the gateway writes session transcript data, potentially creating or appending files arbitrarily on the host filesystem. This may cause configuration corruption or denial of service depending on deployment and filesystem permissions. There is no direct remote code execution impact confirmed.

A patch is available and should be applied. Upgrade OpenClaw to version 2026.2.12 or later, preferably 2026.2.13 or newer, to ensure the session transcript file path is properly constrained within the sessions directory. No additional mitigation is required beyond applying the official fix.