Overview
On August 2, 2026, N-able published a security advisory for CVE-2026-18577, an authentication bypass vulnerability affecting N-central that was discovered being exploited in-the-wild after an incomplete fix for an earlier authentication bypass issue, CVE-2026-18556 was disclosed. CVE-2026-18577 allows a remote unauthenticated attacker to bypass authentication and obtain administrative control of vulnerable N-central servers in affected deployments.
N-able N-central is a widely deployed Remote Monitoring and Management (RMM) platform used by managed service providers (MSPs) and enterprise IT teams to centrally administer servers, workstations, network devices, and other managed assets. Because the platform operates with extensive administrative privileges across customer environments, successful compromise of an N-central server can provide attackers with an efficient path to compromise downstream managed systems.
According to N-able, exploitation of CVE-2026-18577 has been observed in the wild since August 1, 2026. Following successful exploitation, attackers leveraged the platform's Take Control functionality to remotely access managed endpoints, and deployed Cloudflare Tunnel (cloudflared) to establish persistent remote access. On August 3, 2026, CVE-2026-18577 was added to CISA’s Known Exploited Vulnerability (KEV) catalog and on August 5, 2026, CVE-2026-18556 was also added to the catalog.
Mitigation guidance
Organizations operating vulnerable N-central deployments should prioritize remediation on an urgent basis, outside of normal patching schedules. Hosted N-central environments are upgraded automatically by the vendor, while on-premise deployments require manual remediation.
Affected versions:
All versions of N-able N-central up to and including version 2026.3.1, prior to Hotfix 1.
Fixed version:
N-able N-central 2026.3.1 Hotfix 1 (2026.3.1.7).
The vendor also recommends:
Upgrading N-central agents after applying the server hotfix.
Reviewing systems for indicators of compromise.
Contacting N-able Support immediately if evidence of compromise is discovered.
Engaging internal incident response teams if malicious activity is identified.
For further information, see the vendor advisory.
IOCs
N-able has published several artifacts that administrators should investigate during incident response.
Endpoint Artifacts:
Presence of a Cloudflared service.
A suspicious svchost.exe located within the user's Documents folder.
Network Indicators:
Administrators should review historical network logs for inbound or outbound communication involving the malicious IP addresses identified by the vendor:
173[.]249[.]252[.]200
87[.]249[.]138[.]34
37[.]19[.]210[.]32
37[.]153[.]90[.]88
92[.]118[.]112[.]181
68[.]235[.]46[.]214
Organizations should also review:
Authentication logs
Administrative account creation or modification
Take Control session activity
Remote management logs
Windows service installation events
To assist affected organizations running N-central, the vendor has provided a detection template for CVE-2026-18577, which organizations can use to help identify potential compromise.
Rapid7 customers
Exposure Command, InsightVM, and Nexpose
Exposure Command, InsightVM, and Nexpose customers can assess exposure to CVE-2026-18577 and CVE-2026-18556 with vulnerability checks available in the August 4 content release. Note that potential check type must be enabled in the scan template before scanning.
Updates
August 4, 2026: Initial publication.
- August 4, 2026: Updated Rapid7 customers section to reflect the availability of vulnerability checks.
- August 7, 2026: Updated the Overview and Rapid7 Customers sections to indicate addition of CVE-2026-18556 to CISA KEV and availability of vulnerability checks.