[KEV] CVE-2026-18556 -- CVSS 0.0 Vulnerability Briefing

[KEV] CVE-2026-18556 | CVSS 0.0 (Low) | Exploit: Operational

What Is It

CVE-2026-18556 is an authentication bypass vulnerability in N-able N-central that affects its authentication mechanisms through an alternate path or channel.

Technical Detail

The flaw allows an attacker to bypass authentication controls by using an alternate access path or channel. Successful exploitation could permit unauthorized access to N-central functionality without valid credentials. Technical details regarding the specific affected endpoint, protocol, or bypass method have not been confirmed in the available data.

Exploitation Status

CISA has confirmed active exploitation in the wild. Exploit maturity is assessed as Operational, meaning the exploit is sufficiently developed for practical use by attackers rather than being limited to a proof of concept.

Who Is Targeting This

No specific threat actor attribution at this time.

What To Do

Treat this vulnerability as a priority remediation issue and apply N-able security updates or mitigations for N-central as soon as they are available. CISA added this vulnerability to the Known Exploited Vulnerabilities Catalog on August 4, 2026; federal civilian executive branch agencies must patch by August 25, 2026, or apply mitigations. Until remediation is complete, restrict access to N-central management interfaces to trusted administrative networks, review authentication and access logs for unexpected successful sessions or administrative activity, and investigate access that does not align with normal authentication workflows.