CVE-2026-63403CVE-2026-63403

Faktory is a language-agnostic background job server. In versions prior to 1.10.0, the server is vulnerable to an unauthenticated denial of service in which a single malformed command crashes the entire process. Its wire protocol is line-based, and several command handlers slice or index the received line at a fixed offset, such as cmd[5:] for PUSH or qs[0] for QUEUE, without checking that a payload is present. Sending a bare verb with no payload, for example PUSH, ACK, FAIL, BEAT, PUSHB, or QUEUE, triggers a Go slice or index out-of-range panic. Because the codebase has no recover() anywhere in the command-dispatch path, an unrecovered panic in a handler goroutine terminates the whole Go process rather than just that connection, instantly disconnecting every other client, worker, and in-flight job. The attack requires only a connection to the command port and completion of the trivial handshake, with no credentials when no password is configured, and can be repeated to keep the servic