# CVE-2026-77059: boneIO Black TOCTOU race condition in timezone_sudoers

Source: https://junglewise.ai/threats/cve-2026-77059-boneio-black-contains-a-toctou-race-condition-in-the-create  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-77059 · Severity: info · Published 2026-10-26

boneIO Black is a home automation controller that manages electrical devices through a web interface. A race condition in the timezone configuration function allows a local attacker to inject malicious sudoers rules during a window between validation and installation, gaining root-level privileges. This affects systems where untrusted local users have access to the controller.

Technologies: [boneIO Black](https://junglewise.ai/threats/technologies/boneio-black). Vendors: [boneIO](https://junglewise.ai/threats/vendors/boneio).

## Quick answers

**Is CVE-2026-77059 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77059 being exploited in the wild.

**How severe is CVE-2026-77059?** Informational severity, published 26 October 2026.

**Which products and versions are affected?** boneIO Black before 1.6.0.

**Is there a fix for CVE-2026-77059?** Yes: fixed in 1.6.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-77059 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-77059?** Check whether you run boneIO Black at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.6.0

## Technical details

A TOCTOU (time-of-check-time-of-use) race condition exists in create_timedatectl_sudoers_file() in boneio/webui/routes/timezone_sudoers.py, where sudoers rules are written to a predictable temporary file, validated, then installed with root privileges. A local attacker can exploit the validation-to-installation window to substitute malicious content or leverage the predictable filename for symlink attacks, resulting in arbitrary sudoers rule injection and local privilege escalation.

## Affected products

- boneIO Black before 1.6.0

## Timeline

- 2026-10-26: disclosed

## References

- [https://pypi.python.org/](https://pypi.python.org/)
- [https://boneio.eu/en/docs/black](https://boneio.eu/en/docs/black)

## Related threats

- [boneIO Black web interface clickjacking vulnerability](https://junglewise.ai/threats/cve-2026-77062-the-boneio-black-web-interface-lacks-proper-clickjacking)
- [boneIO Black authentication bypass on API endpoints](https://junglewise.ai/threats/cve-2026-77061-boneio-black-directly-excludes-several-api-endpoints-from-the)
- [boneIO Black Cross-Site Request Forgery on state-changing API endpoints](https://junglewise.ai/threats/cve-2026-77058-boneio-black-is-vulnerable-to-cross-site-request-forgery-csrf-on)
- [boneIO Black brute-force attacks on web and SSH](https://junglewise.ai/threats/cve-2026-77057-boneio-black-does-not-limit-authentication-attempts-on-its-web)
- [boneIO Black cleartext password storage in config endpoint](https://junglewise.ai/threats/cve-2026-77054-boneio-black-stores-passwords-including-the-mqtt-broker-and-web)