CVE-2026-77059 boneIO CVE debrief

Who should care

Defenders responsible for boneIO Black deployments should assess exposure and prioritize verification and remediation. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance, and plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Why it matters

Defenders should care about CVE-2026-77059 because it allows local attackers to escalate privileges to root, inject malicious sudoers rules, and potentially conduct symlink attacks. Affected boneIO Black deployments should verify and upgrade to version 1.6.0 or later, and monitor local systems for suspicious activity.

• Local privilege escalation to root
• Arbitrary sudoers rule injection
• Potential for symlink attacks using predictable filename

Technical summary

The create_timedatectl_sudoers_file() function in boneIO Black writes sudoers rules to a predictable temporary file, validates them, then installs them with root privileges. A local attacker can exploit the race window between validation and installation to substitute malicious content, or use the predictable filename for symlink attacks, resulting in arbitrary sudoers rule injection and local privilege escalation to root.

Defensive priority

Defenders should prioritize verifying and upgrading to boneIO version 1.6.0 or later, and monitoring local systems for suspicious activity.

Recommended defensive actions

• Verify and upgrade to boneIO version 1.6.0 or later
• Monitor local systems for suspicious activity
• Review and validate sudoers rules
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the TOCTOU race condition in boneIO Black, including the affected version and fixed version. The issue allows local attackers to inject malicious sudoers rules and escalate privileges to root. Evidence is limited to the CVE record and source item, and defenders should verify and upgrade to version 1.6.0 or later, and monitor local systems for suspicious activity.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.