# CVE-2026-18556 — N-able N-central

> As of 2026-08-01, CVE-2026-18556 is a High-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in N-able N-central, CVSS v4.0 8.2, EPSS 0.2% (19.1th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-18556, most recently “N-able N-central Authentication Bypass Flaws (CVE-2026-18556, CVE-2026-18577) Actively Exploited for Admin Access and Cloudflare Tunnel Persistence”.

**Last updated:** 2026-08-01

## What is CVE-2026-18556?

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.

The record classifies CVE-2026-18556 under weakness class [CWE-288](https://cwe.mitre.org/data/definitions/288.html). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 43 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 8.2 — High (derived from score) (`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`)
- **EPSS (FIRST):** 0.2% probability of exploitation in the next 30 days, higher than 19.1% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-01

## Is CVE-2026-18556 being exploited?

No public exploitation evidence for CVE-2026-18556 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-08-01. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- **N-able**: N-central

## How to fix CVE-2026-18556

No vendor patch reference has been recorded for CVE-2026-18556 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-18556

2 tracked threats in the Threadlinqs corpus reference CVE-2026-18556, either in the campaign’s CVE list or as an indicator on the campaign record.

- [N-able N-central Authentication Bypass Flaws (CVE-2026-18556, CVE-2026-18577) Actively Exploited for Admin Access and Cloudflare Tunnel Persistence](https://intel.threadlinqs.com/threat/TL-2026-1941) — HIGH · 2026-08-08
- [N-able N-central Authentication Bypass (CVE-2026-18577) Actively Exploited for Admin Takeover](https://intel.threadlinqs.com/threat/TL-2026-1830) — CRITICAL · 2026-08-03

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-08-03. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [uptime.n-able.com](https://uptime.n-able.com/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-18556
Full detection coverage and IOCs for threats exploiting CVE-2026-18556 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp