# CVE-2026-18556: N-able N-central Authentication Bypass Using an Alternate Path or Channel

> Unauthenticated attackers can bypass authentication to take over administrative accounts in N-able N-central.

- **Severity:** High 8.2 (`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`)
- **Exploited in the wild:** Yes, since 4 Aug 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** GHSA-fffv-7w63-p3xw

## What is CVE-2026-18556?

CVE-2026-18556 is a high-severity authentication bypass vulnerability in N-able N-central, published on 1 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2026-18556?

It affects 1 product.


Products: N-Able N-Central.

## How do I fix CVE-2026-18556?

No fix has been published for CVE-2026-18556 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 7 Aug 2026.

## Is CVE-2026-18556 being exploited?

Yes. Attackers have exploited CVE-2026-18556 in the wild since at least 4 Aug 2026.

Public exploit code:

- Read-only N-able N-central CVE-2026-18556/CVE-2026-18577 post-exploitation IoC hunter for Windows endpoints (github_poc): https://github.com/CreamyG31337/ncentral-compromise-ioc-triage

## Other vulnerabilities in N-able N-central

- [CVE-2026-86218](https://insights.sbomify.com/CVE-2026-86218/): N-able N-central Static Code Injection (critical 10.0, exploited in the wild)
- [CVE-2025-8875](https://insights.sbomify.com/CVE-2025-8875/): N-able N-Central Insecure Deserialization (critical 9.4, exploited in the wild)
- [CVE-2025-8876](https://insights.sbomify.com/CVE-2025-8876/): N-able N-Central Command Injection (critical 9.4, exploited in the wild)
- [CVE-2026-18577](https://insights.sbomify.com/CVE-2026-18577/): N-able N-central Authentication Bypass Using an Alternate Path or Channel (high 8.2, exploited in the wild)
- [CVE-2025-11367](https://insights.sbomify.com/CVE-2025-11367/): N-central windows software probe Remote Code Execution (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18556 and fix it if it is affected.

What it is: CVE-2026-18556 is a high-severity authentication bypass vulnerability in N-able N-central, published on 1 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-18556 in the wild since at least 4 Aug 2026.

Affected product: N-able N-central. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18556/ (Markdown: https://insights.sbomify.com/CVE-2026-18556/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18556
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18556
- OSV: https://osv.dev/vulnerability/CVE-2026-18556

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18556/
Summaries are generated and may contain mistakes; the official description above is the record.