CVE-2026-18556
KEV: known exploited SSVC: activeUnauthenticated administrative account takeover
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Attack conditions and impact
Derived from the NVD CVSS 3.1 vectorThis vulnerability may be exploitable over the internet without authentication or user interaction.
| Metric | Value | Meaning |
|---|---|---|
| Attack vector AV | N | Network |
| Attack complexity AC | H | High (conditions required) |
| Privileges required PR | N | None |
| User interaction UI | N | None |
| Scope S | U | Unchanged |
| Confidentiality C | H | High |
| Integrity I | H | High |
| Availability A | N | None |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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.
CISA KEV entry
N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability — N-able / N-central
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.
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
CVSS assessments
| Provider | Version | Score | Vector |
|---|---|---|---|
| NVD / a5532a13-c4dd-4202-bef1-e0b8f2f8d12b (Secondary) | 4.0 | 8.2 HIGH | 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 |
| NVD / [email protected] (Primary) | 3.1 | 7.4 HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA / N-able | 4.0 | 8.2 HIGH | 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 |
Affected products and packages
CNA (CVE.org)
| Vendor | Product | Versions |
|---|---|---|
| N-able | N-central | affected: 0 … <= 2026.1 default: unaffected |
NVD CPE (1)
Show CPE list
| Vendor | Product | Range | CPE |
|---|---|---|---|
| n-able | n-central | <= 2026.1 | cpe:2.3:a:n-able:n-central:*:*:*:*:*:*:*:* |
Linux distribution status
References (3)
- https://uptime.n-able.com/ NVD, CNA Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-18556 NVD, ADP CISA-ADP US Government Resourcegovernment-resource
- https://www.n-able.com/blog/n-central-security-update-august-2-2026 NVD, ADP CISA-ADP Vendor Advisoryvendor-advisory