CVE-2026-18556

Published Aug 1, 2026

Last updated 15 hours ago

Exploit known CVSS high 8.2

N-central

Zero-day

N-able N-central

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-18556 describes an authentication bypass vulnerability found in N-able N-central, impacting versions up to and including 2026.1. This flaw, categorized as an "unauthenticated administrative account takeover," stems from an alternate path or channel that allows for authentication bypass (CWE-288). The vulnerability enables an unauthenticated attacker to circumvent existing authentication mechanisms and gain unauthorized administrative access to N-able N-central servers. N-able initially released a fix for this issue in version 2026.2, but a subsequent discovery revealed an incomplete patch, leading to a related vulnerability, CVE-2026-18577, which affected builds prior to 2026.3.1.7.

Description: Authentication bypass using an alternate path or channel vulnerability in N-able N-central allows Authentication Bypass. This issue affects N-central: through 2026.1.
Source: a5532a13-c4dd-4202-bef1-e0b8f2f8d12b
NVD status: Analyzed
Products: n-central

Risk scores

CVSS 4.0

Type: Secondary
Base score: 8.2
Impact score: -
Exploitability score: -
Vector string: 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
Severity: HIGH

CVSS 3.1

Type: Primary
Base score: 7.4
Impact score: 5.2
Exploitability score: 2.2
Vector string: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity: HIGH

Known exploits

Data from CISA

Vulnerability name: N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability
Exploit added on: Aug 4, 2026
Exploit action due: Aug 7, 2026
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.

Weaknesses

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

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score: 16

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:n-able:n-central:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "4BC10DA8-8B50-4BCA-A302-810F4E3CD4CB",
            "versionEndIncluding": "2026.1",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.