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Full vulnerability report · 2026
CVE-2026-18556High confidence

N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability

N-able · N-central

8.2HighCVSS 4.0
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2026-08-07 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 4 Aug 2026

Evidence used

  • CISA confirms exploitation in the wild.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 7.88% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs N-able N-central and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-51918

CISA KEV mirrored by ENISA

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.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 4 Aug 2026. Evidence sources: cisa_kev.
ENISA score
8.2 · CVSS 4.0
Advisory evidence
1 linked advisory record
Explicit mitigation evidence

Only statements that explicitly mention a fix, patch, update, workaround or mitigation are shown here.

  • csaf_ncscnl · NCSC-2026-0275Kwetsbaarheden verholpen in N-able N-central
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2026-08-07 as the remediation due date.

Patch available
01

What, why and how

N-able N-central contains an authentication bypass using an alternate path or channel that allows for authentication bypass.

What

N-able N-central contains an authentication bypass using an alternate path or channel that allows for authentication bypass.

Why

The product requires authentication, but the product has an alternate path or channel that does not require authentication.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may bypass an access boundary or take over an account.

What

N-able N-central contains an authentication bypass using an alternate path or channel that allows for authentication bypass.

Why

The product requires authentication, but the product has an alternate path or channel that does not require authentication.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may bypass an access boundary or take over an account.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-08-04.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Authentication Bypass Using an Alternate Path or Channel → bypass an access boundary or take over an account
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-288 ↗

CWE-288: Authentication Bypass Using an Alternate Path or Channel. The product requires authentication, but the product has an alternate path or channel that does not require authentication.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
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

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
NetworkUnauthenticatedCWE-288CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-51918Known-exploited evidence recorded

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.

Official EUVD record ↗
BSI · German · WID-SEC-2026-2621N-able N-Central: Mehrere Schwachstellen ermöglichen Umgehen von Sicherheitsvorkehrungen

Ein Angreifer kann mehrere Schwachstellen in N-able N-Central ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV26-769N-able security advisory (AV26-769) - Update 2

As of August 2, 2026, N-able is affected by vulnerabilities in the following product: On August 3, 2026, Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2026-18577 to their Known Exploited Vulnerabilities (KEV) Database.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260805Security Bulletin 5 Aug 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 5 Aug 2026, published on 5 August 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-026954n-ableのn-centralにおける代替パスまたはチャネルを使用した認証回避に関する脆弱性

N-able N-central における代替パスまたはチャネルを使用した認証バイパスの脆弱性により、認証がバイパスされる可能性があります。この問題は N-central: 2026.1 までのバージョンに影響します。

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-026953n-ableのn-centralにおける代替パスまたはチャネルを使用した認証回避に関する脆弱性

CVE-2026-18556の不完全なパッチにより、2026年3月1日までのN-centralのバージョンで認証バイパスおよびアカウントの乗っ取りが可能となります。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6899美 CISA 발표 주요 Exploit 정보공유(Update. 2026-08-04)

N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6897美 CISA 발표 주요 Exploit 정보공유(Update. 2026-08-03)

N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0275Kwetsbaarheden verholpen in N-able N-central

De kwetsbaarheden betreffen bypass van authenticatie in N-able N-central. In versies tot en met 2026.1 kan een aanvaller de authenticatiecontroles omzeilen door een alternatieve route binnen de applicatie te benutten. In versies tot en met 2026.3.1 is een onvolledige patch voor de kwetsbaarheid met kenmerk CVE-2026-18556 geïntroduceerd die authenticatieomzeiling en overname van accounts mogelijk maakt. Dit issue heeft kenmerk CVE-2026-18577 toegewezen gekregen. Hierdoor kan een aanvaller ongeautoriseerd toegang krijgen tot gebruikersaccounts en het systeem controleren. Alle implementaties die de genoemde versies gebruiken, zijn kwetsbaar. N-able meldt dat misbruik van de kwetsbaarheid is ontdekt en hierop gebruikers heeft geïnformeerd.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
N-central: 0 ≤ 2026.1
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 1 Aug 2026 · Last source change 5 Aug 2026, 03:56 UTC · CWE-288 · Authentication Bypass Using an Alternate Path or Channel

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-51918
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    ≤ 2026.1 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    N-central: ≤ 2026.1 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-51918↗CISA KEV record↗CVE authority or vendor reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-18556 · cve.blacktree.nl