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CVE ID

# CVE-2026-18556

Published 2026-08-01

Updated 19 days ago

Vendor/s

N-able

Product/s

N-central

Version/s

\* > 2026.1

KEV Status

Active Exploitation

Listed in CISA's Known Exploited Vulnerabilities catalog. Active exploitation observed in the wild.

CVSS Score (v3.1)

7.4

/ 10

High

Severity Details

Base score

7.4 High

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Table of Contents

[Description ](#description)[Why this matters ](#why-this-matters)[CPE ](#cpe)[Related weakness (CWE) ](#cwe)[Remediation plan ](#remediation)[Detection Guidance ](#detection-guidance)[References ](#references)[Sources](#sources)

[Description ](#description)[Why this matters ](#why-this-matters)[CPE ](#cpe)[Related weakness (CWE) ](#cwe)[Remediation plan ](#remediation)[Detection Guidance ](#detection-guidance)[References ](#references)[Sources](#sources)

## Description

CVE-2026-18556 is a high-severity authentication bypass in N-able N-central (up to v2026.1) that is actively exploited in the wild.

## Why this matters

"CVE-2026-18556 is a critical security concern because it allows attackers to bypass authentication in N-able N-central, a widely used Remote Monitoring and Management (RMM) platform. With a CVSS score of 7.4 and its inclusion in CISA’s Known Exploited Vulnerabilities (KEV) catalog, this flaw is actively being targeted by threat actors. Successful exploitation grants unauthorized access to the management console, potentially leading to full control over managed client environments. Given N-central's role in service provider infrastructure, this vulnerability poses a significant risk for large-scale supply chain compromises and lateral movement across customer networks."

## CPE

N-able

| Product   | Version Start | Version End (excl.) | Status     |
| --------- | ------------- | ------------------- | ---------- |
| n-central | \*            | 2026.1              | vulnerable |

## Related weakness (CWE)

CWE-288

## Remediation plan

1

### Apply official patches

Immediately install the latest security updates provided by N-able, specifically N-central 2026.3 Hotfix 1 or the most recent stable release that addresses the alternate path authentication bypass.

2

### Update affected systems

Identify all N-central instances within your environment running version 2026.1 or earlier and upgrade them to a patched version to eliminate the vulnerability.

3

### Restrict access

Implement strict network access control lists (ACLs) to limit access to the N-central administrative interface to known, trusted IP addresses or require access via a secure VPN.

4

### Monitor for exploitation

Conduct a forensic review of authentication logs for any successful logins originating from unusual geographic locations or sessions that appear to bypass standard multi-factor authentication (MFA) workflows.

## Detection Guidance

"Monitor N-central web server logs for requests to unusual or undocumented URL paths that may bypass standard login prompts. Look for successful authentication events that do not correlate with known user activity or MFA challenges. Additionally, inspect network traffic for unauthorized administrative traffic originating from external IP addresses and review audit logs for the creation of unauthorized administrative accounts or unexpected configuration changes."

## References

[https://uptime.n-able.com/ Vendor Advisory ](https://uptime.n-able.com/)[https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field\_cve=CVE-2026-18556 US Government Resource ](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-18556)[https://www.n-able.com/blog/n-central-security-update-august-2-2026 Vendor Advisory](https://www.n-able.com/blog/n-central-security-update-august-2-2026)

## Sources

NIST National Vulnerability Database (NVD)

CISA Known Exploited Vulnerabilities (KEV)

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