Openclaw cli: OpenClaw: Zalo channel downloads media before sender authorization (CVE-2026-33576)

The vulnerability in OpenClaw CLI's Zalo channel component caused inbound media to be fetched and stored before direct message or pairing authorization checks were performed. This flaw allowed unauthorized senders to force the application to perform network fetches and write media files to disk despite the message being rejected later. The affected code was in the file extensions/zalo/src/monitor.ts. The issue was resolved by gating image downloads until after authorization checks, with the fix committed in 68ceaf7a5f and included starting from version 2026.3.28.

An attacker who is not authorized to send messages could cause the application to download media from the network and write it to disk. This could lead to unauthorized network activity and disk writes, potentially exposing the system to further risks such as disk space exhaustion or introduction of malicious media files. The vulnerability has a high CVSS score of 9.8, indicating critical impact on confidentiality, integrity, and availability.

A patch is available and should be applied. Users should upgrade OpenClaw CLI to version 2026.3.28 or later, which contains the fix that gates image downloads until after direct message authorization checks complete. No other mitigation is indicated or required.