CVE-2026-18577: N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability

What it is

N-able N-central contains an authentication bypass using an alternate path or channel allows for authentication bypass and account takeover in N-central. This vulnerability is the result of an incomplete patch for CVE-2026-18556.

What to do

Treat this as urgent. Identify every affected system, starting with anything internet-facing, and apply the vendor fix or mitigation within days. If you cannot patch quickly, isolate or disable the affected service and watch for signs of compromise.

Priority

Act now: Patch or mitigate internet-facing systems within days.

Severity (CVSS)

8.2 high

CISA assessment (SSVC)

actively exploited; attackers can automate it at scale; total control of the affected system

Exploit probability (EPSS, 30 days)

15%, higher than 96% of all CVEs

Added to CISA KEV

3 August 2026

CISA fix-by date

6 August 2026 (US federal agencies; a sensible deadline for everyone)

Ransomware use

Not known

Weakness

CWE-288

References

• NIST NVD entry
• CISA KEV entry
• documentation.n-able.com/N-central/Release_Notes/GA/Content/N-central_2026.3_HF1
• status.n-able.com/2026/08/02/n-central-2026-3-hotfix-1-mitigation-for-cve-2026-1
• www.cve.org/CVERecord?id=CVE-2026-18556
• www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-18577
• www.n-able.com/blog/n-central-security-update-august-2-2026

Sources: CISA Known Exploited Vulnerabilities · FIRST Exploit Prediction Scoring System (EPSS) · NIST National Vulnerability Database · CISA Vulnrichment (SSVC), via the CVE Program. This product uses data from the NVD API but is not endorsed or certified by the NVD. Summaries are machine-written from CISA’s description; treat the vendor’s advisory as the authority for fixes.