CVE-2026-63404

Deferred Deferred - Pending Action

Insecure Temporary File in Faktory Leading to Root Privilege Escalation

Publication date: 2026-08-25

Last updated on: 2026-09-09

Assigner: GitHub, Inc.

Description

Faktory is a language-agnostic background job server. In versions prior to 1.10.0, the embedded Redis bootstrapper is vulnerable to an insecure temporary file flaw that lets a local unprivileged user hijack the Redis configuration and escalate to root. It writes its startup configuration to a fixed, predictable, world-writable path, /tmp/redis.conf, only creating the file if it does not already exist and never validating it on later boots. Because /tmp is world-writable, a local unprivileged user can pre-create /tmp/redis.conf with attacker-chosen Redis directives before Faktory starts, and Faktory will use the planted file verbatim. Faktory only overrides the unixsocket, dir, and logfile options, leaving directives such as bind, protected-mode, requirepass, and loadmodule attacker-controlled. This lets an attacker silently expose the entire job queue over an unauthenticated network port with no visible error to the administrator. Because the official systemd unit runs Faktory, and the redis-server child it spawns, as root, an attacker can also supply a loadmodule directive to execute arbitrary native code in the root-owned Redis process, escalating from a local unprivileged user to root. This issue is fixed in version 1.10.0.

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Meta Information

Published

2026-08-25

Last Modified

2026-09-09

Generated

2026-09-15

AI Q&A

2026-08-26

EPSS Evaluated

2026-09-13

NVD

CVE-2026-63404

Affected Vendors & Products

Vendor	Product	Version / Range
contribsys	faktory	to 1.10.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-377	Creating and using insecure temporary files can leave application and system data vulnerable to attack.

Attack-Flow Graph

Executive Summary

Faktory versions before 1.10.0 have a vulnerability where the Redis bootstrapper writes its startup configuration to a predictable, world-writable path (/tmp/redis.conf). A local unprivileged user can pre-create this file with malicious Redis directives, causing Faktory to use it. This allows attackers to expose job queues over an unauthenticated network port or execute arbitrary code as root via the loadmodule directive.

Detection Guidance

Check for the presence of /tmp/redis.conf file. If it exists and is world-writable, it may indicate exploitation. Inspect Faktory logs for unexpected Redis configuration errors or unauthorized access attempts.

Impact Analysis

An attacker could gain unauthorized access to job queues, manipulate background tasks, or escalate privileges to root. This could lead to data breaches, service disruptions, or complete system compromise if the Faktory server runs as root.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data processed by background jobs, violating GDPR's data protection requirements or HIPAA's security rules. Compliance may be compromised due to potential data exposure or unauthorized system access.

Mitigation Strategies

Upgrade Faktory to version 1.10.0 or later immediately. Remove any existing /tmp/redis.conf file and ensure no untrusted users have write access to /tmp. Monitor for unauthorized Redis processes or network exposure.

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