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

BOD 26-04 remediation window

With CISA's SSVC answers for this CVE (automatable: yes, technical impact: total), BOD 26-04 Table 1 gives 3 days and forensic triage on a publicly exposed asset (row 1) and 3 days and forensic triage on an asset that is not publicly exposed (row 9) ^S06. CISA set the catalogue due date at 3 days; under BOD 26-04 it reflects CISA's own view of whether the flaw sits on publicly exposed assets ^S07. The directive binds US federal civilian executive branch agencies only.

What CISA says

Short description

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

Required action

Apply 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.

Notes

https://uptime.n-able.com/ ; https://status.n-able.com/2026/08/02/n-central-2026-3-hotfix-1-mitigation-for-cve-2026-18577/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-18556

CWE in the catalogue

CWE-288

Official links

• CISA KEV catalogue entry cisa.gov
• NVD record nvd.nist.gov

Vendor advisory and patch links

References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.

• https://uptime.n-able.com/ Vendor Advisory
• https://www.n-able.com/blog/n-central-security-update-august-2-2026 Vendor Advisory

Links in CISA's notes

• https://uptime.n-able.com/
• https://status.n-able.com/2026/08/02/n-central-2026-3-hotfix-1-mitigation-for-cve-2026-18577/
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
• https://nvd.nist.gov/vuln/detail/CVE-2026-18556

NVD details

CWE (NVD)

CWE-288 by a5532a13-c4dd-4202-bef1-e0b8f2f8d12b

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS versions in NVD

V31, V40

Last modified in NVD

2026-10-23T22:10:00.160

Where each value comes from

This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.