What is CVE-2026-18556?

CVE-2026-18556 is Unauthenticated administrative account takeover. The supplied enrichment data classifies it as Auth Bypass mapped to CWE-288 Authentication Bypass Using an Alternate Path.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

13 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, identity provider logs, authentication audit logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-18556 using CVSS 7.4, EPSS 40%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

Publicly linked actor or ransomware signals in the supplied enrichment data: UTA0533 (), Kimsuky (), APT37 (), UNC6671 (), Bookworm (). Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVhighAuth Bypasspublic exploit

CVE-2026-18556

CVE-2026-18556 — Unauthenticated administrative account takeover

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2026-18556 in CISA KEV with required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

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.

Published Aug 1, 2026Updated Aug 5, 2026Sources: NVD, N-able (CNA), CISA, FIRST EPSS, GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Aug 4, 2026

EPSS

40%

ahead of 99% of scored CVEs

Affects

N-able

N-central

CVSS base

7.4

high · 2 sources

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade N-central to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Federal deadline Aug 7, 2026 — passed 42 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
N-able	N-central	0 to <= 2026.1	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

None

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

High

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
7.4	CVSS 3.1	high	2.2	5.2	NVD
8.2	CVSS 4.0	high	—	—	N-able (CNA)

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-288 · Authentication Bypass Using an Alternate Path or Channel

Bypass Protection Mechanism::

Mitigation: Funnel all access through a single choke point to simplify how users can access a resource. For every access, perform a check to determine if the user has permissions to access the resource.::

Weakness & attack patterns

CWE-288Authentication Bypass Using an Alternate Path

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-127 · Directory Indexing

T1083File and Directory Discovery
T1211Exploitation for Defensive Evasion
T1542.002Pre-OS Boot: Component Firmware

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Aug 4, 2026

Federal deadline

Aug 7, 2026

passed 42 days ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Exploit entries

Exploit-DB and CTI exploit indexes

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

26 more posts on this CVEShowing 5 of 31 · Who is discussing this CVE, and how loudlyUnlock free

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Prioritize edge telemetry for network-reachable N-central.
Monitor for scanner or exploit-pattern traffic after 13 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPSidentity provider logsauthentication audit logs

Groups associated with this CVE

Groups reported in connection with this vulnerability. A reported association, not a confirmed observation of that group using it — and not scoped to any sector or campaign.

UTA0533KimsukyAPT37UNC6671Bookworm

3 more threat groups on this CVEShowing 5 of 8 · Attribution, campaigns and the malware each one runsUnlock free

ip68.235.46.21476
AbuseIPDB Hourly Update · Oct 24, 2024
ip37.19.210.3268
StopForumSpam-Firehol · Jul 5, 2022
ip37.153.90.8855
Cyber Threat Alliance (CTA) Premium · Jun 29, 2026
ip173.249.252.20074
AbuseIPDB Hourly Update · Feb 7, 2026
ip23.234.94.4344
AbuseIPDB Hourly Update · Sep 29, 2025

2 more indicators on this CVEShowing 5 of 7 · Hashes, addresses and domains from a live threat exchangeUnlock free

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Cve is exploited CreamyG31337/ncentral-compromise-ioc-triage
Aug 6, 2026 · SOCRadar CTI
Added · CVSS 3.1 7.4 (AV:N)
Aug 5, 2026 · NVD
Added to CISA KEV catalog
Aug 4, 2026 · CISA
Initial · CVE published
Aug 1, 2026 · NVD
CVE published by MITRE.
Aug 1, 2026 · SOCRadar CTI

Source activity

Readings a source repeats on a schedule, counted rather than listed.

17×SvrsAug 3, 2026 – Aug 28, 2026 · SOCRadar CTI
10×TweetsAug 2, 2026 – Aug 12, 2026 · SOCRadar CTI
5×ModifiedAug 1, 2026 – Aug 5, 2026 · SOCRadar CTI
2×TelegramAug 3, 2026 – Aug 4, 2026 · SOCRadar CTI
1×Github_Repos · Github repository created, CreamyG31337/ncentral-compromise-ioc-triageAug 6, 2026 · SOCRadar CTI
1×CVE appeared in the Cve Trends.Aug 4, 2026 · SOCRadar CTI

References

7 on the record

uptime.n-able.com/
Vendor Advisory, NIST
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-18556
US Government Resource, NIST
www.n-able.com/blog/n-central-security-update-august-2-2026
Vendor Advisory
status.n-able.com/2026/08/02/n-central-2026-3-hotfix-1-mitigation-for-cve-2026-18577/
Vendor Advisory
www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
US Government Resource
www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
US Government Resource
nvd.nist.gov/vuln/detail/CVE-2026-18556
Vendor Advisory

Coverage

21 stories from the feeds we poll

16 more reports on this CVEShowing 5 of 21 · Vendor research and security press coverageUnlock free

Elsewhere on this site

N-ableevery CVE for this vendor
August 2026what else CISA listed
Auth Bypasssame class
CWE-288other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

Only the 5 indicator(s) reported for this CVE are available; no packet-level or host-forensic artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-18556 is Unauthenticated administrative account takeover, a high vulnerability affecting N-central from N-able. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 13 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.4 describes technical severity, while EPSS 40% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.