CVE-2026-18556: N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability

Summary

N-able N-central contains an authentication bypass using an alternate path or channel that allows for authentication bypass.

Remediation

Inventory every N-able N-central deployment, including staging.
No fixed version appears in the public sources yet. Check the references below and the vendor directly.
Review logs from before the change for signs of exploitation.

CISA required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

References

Advisoryhttps://uptime.n-able.com/
Advisoryhttps://status.n-able.com/2026/08/02/n-central-2026-3-hotfix-1-mitigation-for-cve-2026-18577/
Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
Advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-18556
Advisoryhttps://www.n-able.com/blog/n-central-security-update-august-2-2026
Referencehttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-18556