CVE Catalog

CVE-2026-63403

HighCVSS 8.7
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.43%

35th percentile - higher than 35% of all known CVEs

Summary

Faktory prior to version 1.10.0 is vulnerable to an unauthenticated denial of service where a single malformed command crashes the entire process. The wire protocol is line-based, and several command handlers slice or index the received line without checking for a payload, causing a Go slice or index out-of-range panic. The attack requires only a connection to the command port and completion of the trivial handshake, with no credentials when no password is configured.

Risk Assessment

An attacker can repeatedly send malicious commands, causing continuous service outages, disconnecting all clients and workers, and preventing job processing.

Recommendation

Upgrade the Faktory server to version 1.10.0 or later, which includes a fix for the panic vulnerability.

Related vulnerabilities

Original NVD description (English source)

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 service down indefinitely. This issue is fixed in version 1.10.0.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS