CVE-2026-18577: N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability

Q: How do I fix CVE-2026-18577?

n-central: upgrade to 2026.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-18577 being exploited?

Yes. CVE-2026-18577 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2026-18577 affect?

CVE-2026-18577 affects n-central. Severity is high (CVSS 8.1). An incomplete patch for CVE-2026-18556 allows for authentication bypass and account takeover in N-central Versions through 2026.3.1

Q: How urgent is CVE-2026-18577?

Priority 86/100. High severity; EPSS top 3%: very likely to be exploited; Exploited in the wild (CISA KEV); CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Patch now

HIGH 8.1EXPLOITEDREMOTEUPGRADE

CVE-2026-18577 is a high-severity flaw (CVSS 8.1) affecting n-central, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An incomplete patch for CVE-2026-18556 allows for authentication bypass and account takeover in N-central Versions through 2026.3.1

Why this priority

High severity
EPSS top 3%: very likely to be exploited
Exploited in the wild (CISA KEV)
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	14.6% (top 3%)
CISA exploited list	Yes, fix due 2026-08-06
Weakness	CWE-288
Published	2026-08-02
Last modified	2026-10-23

Publisher (CNA): N-able · Vendor: n-able

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-02 23:16 UTCPublished CVE record published
2026-08-03Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-08-06Deadline CISA due date for US federal agencies to patch
2026-10-23 22:10 UTCUpdated Record last modified

n-able n-central UPGRADE

Affected: < 2026.3 · 2026.3

Fixed in: 2026.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy n-central || rpm -q n-central || n-central --version

2. UPGRADE to 2026.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade n-central

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade n-central

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · pspp · FIXED · 2.1.3-2.fc46 · FEDORA-2026-0d6444911b · source

sudo dnf upgrade --advisory=FEDORA-2026-0d6444911b

Fedora ELN · barman · FIXED · 3.20.1-3.eln159 · FEDORA-2026-45ecf042c2 · source

sudo dnf upgrade --advisory=FEDORA-2026-45ecf042c2

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: HORKimhab/CVE-2026-18577 (0 stars)
Nuclei scan template: N-able N-central < 2026.3.1.10 - Authentication Bypass

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-18577?

n-central: upgrade to 2026.3. Exact commands for each OS are on this page.

Is CVE-2026-18577 being exploited?

Yes. CVE-2026-18577 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-18577 affect?

CVE-2026-18577 affects n-central. Severity is high (CVSS 8.1). An incomplete patch for CVE-2026-18556 allows for authentication bypass and account takeover in N-central Versions through 2026.3.1

How urgent is CVE-2026-18577?

Priority 86/100. High severity; EPSS top 3%: very likely to be exploited; Exploited in the wild (CISA KEV); CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-18556 HIGH 7.4 EXPLOITED UPGRADE N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability
CVE-2025-11700 HIGH 7.5 UPGRADE N-central versions < 2025.4 are vulnerable to multiple XML External Entities injection leading to information
CVE-2025-11367 CRITICAL 9.8 UPGRADE The N-central Software Probe < 2025.4 is vulnerable to Remote Code Execution via deserialization
CVE-2025-11366 CRITICAL 9.8 UPGRADE N-central < 2025.4 is vulnerable to authentication bypass via path traversal
CVE-2026-86218 CRITICAL 9.8 EXPLOITED UPGRADE N-able N-central Static Code Injection Vulnerability

References

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