CVE-2026-18556

HIGHCISA KEV

7.4

CVSS v3

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.

CWE-288

How to fix

Actively exploited, no published fix found yet

Federal remediation due: 2026-08-07

Mitigation guidance may be in the linked vendor advisories in the References section below.

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CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Exploit Intelligence

0.49%probability of exploitation in 30 days

40thpercentile

Low risk: more likely to be exploited than 40% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Remediation due: 2026-08-07

References

Vendor Advisory2

Government Resource1

cisa.gov

Related Vulnerabilities

Other CWE-288 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-42793	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2024-1709	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2024-27198	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2025-4427	Medium	5.3	100%	KEV	Fix
CVE-2024-55591	Critical	9.8	98%	KEV + Ransom	Fix
CVE-2023-46747	Critical	9.8	97%	KEV + Ransom	-

Common questions

How do I fix CVE-2026-18556?

No published fix for CVE-2026-18556 has been found yet. It is on the CISA Known Exploited Vulnerabilities list; federal agencies must remediate by 2026-08-07. Apply the vendor's mitigations per CISA's guidance.

Is CVE-2026-18556 being actively exploited?

Yes. CVE-2026-18556 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2026-08-07. Treat it as a priority whatever its CVSS score says.

How severe is CVE-2026-18556?

CVE-2026-18556 has a CVSS v3 base score of 7.4, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-05.