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Full vulnerability report · 2026
CVE-2026-41940High confidence

WebPros cPanel & WHM and WP2 (WordPress Squared) Missing Authentication for Critical Function Vulnerability

WebPros · cPanel & WHM and WP2 (WordPress Squared)

9.3CriticalCVSS 4.0
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2026-05-03 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • CISA confirms exploitation in the wild.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 98.53% 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 WebPros cPanel & WHM and WP2 (WordPress Squared) 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-2026-26246

EU known exploited

cPanel and WHM versions after 11.40 contain an authentication bypass vulnerability in the login flow that allows unauthenticated remote attackers to gain unauthorized access to the control panel.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 30 Apr 2026. Evidence sources: cisa_kev, eukev_kev.
ENISA score
9.3 · 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-2026-0130Kwetsbaarheid verholpen in cPanel en WHM
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2026-05-03 as the remediation due date.

Patch available
01

What, why and how

WebPros cPanel & WHM (WebHost Manager) and WP2 (WordPress Squared) contain an authentication bypass vulnerability in the login flow that allows unauthenticated remote attackers to gain unauthorized access to the control panel.

What

WebPros cPanel & WHM (WebHost Manager) and WP2 (WordPress Squared) contain an authentication bypass vulnerability in the login flow that allows unauthenticated remote attackers to gain unauthorized access to the control panel.

Why

A security-sensitive function is reachable without the authentication check that should protect it.

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

WebPros cPanel & WHM (WebHost Manager) and WP2 (WordPress Squared) contain an authentication bypass vulnerability in the login flow that allows unauthenticated remote attackers to gain unauthorized access to the control panel.

Why

A security-sensitive function is reachable without the authentication check that should protect it.

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 2026-04-30. Known ransomware campaign use is recorded.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Missing Authentication for Critical Function → bypass an access boundary or take over an account
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-306 ↗

CWE-306: Missing Authentication for Critical Function. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

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:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.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.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.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-306CISA KEVPublic exploit reference
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-26246Known-exploited evidence recorded

cPanel and WHM versions after 11.40 contain an authentication bypass vulnerability in the login flow that allows unauthenticated remote attackers to gain unauthorized access to the control panel.

Official EUVD record ↗
BSI · German · WID-SEC-2026-1310cPanel cPanel/WHM: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein Angreifer kann eine Schwachstelle in cPanel cPanel/WHM ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV26-404cPanel security advisory (AV26-404) – Update 1

On April 28, 2026, cPanel published a security advisory to address vulnerabilities in the following product: On April 30, 2026, Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2026-41940 to their Known Exploited Vulnerabilities (KEV) Database.

Official advisory ↗
Canadian Centre for Cyber Security · English · AL26-008AL26-008 - Vulnerability affecting cPanel and WebHost Manager (WHM) - CVE-2026-41940

An Alert is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide additional detection and mitigation advice to recipients. The Canadian Centre for Cyber Security ("Cyber Centre") is also available to provide additional assistance regarding the content of this Alert to recipients as requested.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260506Security Bulletin 06 May 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 06 May 2026, published on 6 May 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-014273cPanelのcPanel等の複数製品における重要な機能に対する認証の欠如に関する脆弱性

cPanelおよびWHMのバージョン11.40以降には、ログインフローに認証バイパスの脆弱性が存在し、認証されていないリモート攻撃者がコントロールパネルに不正にアクセスする可能性があります。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6774美 CISA 발표 주요 Exploit 정보공유(Update. 2026-04-30)

WebPros cPanel & WHM and WP2 (WordPress Squared) Missing Authentication for Critical Function Vulnerability

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0130Kwetsbaarheid verholpen in cPanel en WHM

cPanel and WHM versions prior to specified releases, including those after 11.40, contain an authentication bypass vulnerability via CRLF injection in session files and login flow, allowing unauthenticated attackers to gain root-level control panel access.

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
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 29 Apr 2026 · Last source change 30 Sept 2026, 17:20 UTC · CWE-306 · Missing Authentication for Critical Function

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-2026-26246
Product sourceCISA KEV
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
    cPanel: 11.40.0.0 < 11.86.0.41, 11.88.0.0 < 11.94.0.28, 11.96.0.0 < 11.102.0.39, 11.104.0.0 < 11.110.0.97, 11.112.0.0 < 11.118.0.63, 11.120.0.0 < 11.124.0.35, 11.126.0.0 < 11.126.0.54, 11.128.0.0 < 11.130.0.19, 11.132.0.0 < 11.132.0.29, 11.134.0.0 < 11.134.0.20, 11.136.0.0 < 11.136.0.5; WHM: 11.40.0.0 < 11.86.0.41, 11.88.0.0 < 11.94.0.28, 11.96.0.0 < 11.102.0.39, 11.104.0.0 < 11.110.0.97, 11.112.0.0 < 11.118.0.63, 11.120.0.0 < 11.124.0.35, 11.126.0.0 < 11.126.0.54, 11.128.0.0 < 11.130.0.19, 11.132.0.0 < 11.132.0.29, 11.134.0.0 < 11.134.0.20, 11.136.0.0 < 11.136.0.5 · Fixed: WP Squared: 11.136.1.7
    After
    cPanel: 11.40.0.0 < 11.86.0.41, 11.88.0.0 < 11.94.0.28, 11.96.0.0 < 11.102.0.39, 11.104.0.0 < 11.110.0.97, 11.112.0.0 < 11.118.0.63, 11.120.0.0 < 11.124.0.35, 11.126.0.0 < 11.126.0.54, 11.128.0.0 < 11.130.0.19, 11.132.0.0 < 11.132.0.29, 11.134.0.0 < 11.134.0.20, 11.136.0.0 < 11.136.0.5; WP Squared: < 11.136.1.7; WHM: 11.40.0.0 < 11.86.0.41, 11.88.0.0 < 11.94.0.28, 11.96.0.0 < 11.102.0.39, 11.104.0.0 < 11.110.0.97, 11.112.0.0 < 11.118.0.63, 11.120.0.0 < 11.124.0.35, 11.126.0.0 < 11.126.0.54, 11.128.0.0 < 11.130.0.19, 11.132.0.0 < 11.132.0.29, 11.134.0.0 < 11.134.0.20, 11.136.0.0 < 11.136.0.5 · 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.
    CISA KEV ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    11.40.0.0 < 11.86.0.41; 11.88.0.0 < 11.94.0.28; 11.96.0.0 < 11.102.0.39; 11.104.0.0 < 11.110.0.97; 11.112.0.0 < 11.118.0.63; 11.120.0.0 < 11.124.0.35; 11.126.0.0 < 11.126.0.54; 11.128.0.0 < 11.130.0.19 · Fixed: 11.136.1.7
    After
    cPanel: 11.40.0.0 < 11.86.0.41, 11.88.0.0 < 11.94.0.28, 11.96.0.0 < 11.102.0.39, 11.104.0.0 < 11.110.0.97, 11.112.0.0 < 11.118.0.63, 11.120.0.0 < 11.124.0.35, 11.126.0.0 < 11.126.0.54, 11.128.0.0 < 11.130.0.19, 11.132.0.0 < 11.132.0.29, 11.134.0.0 < 11.134.0.20, 11.136.0.0 < 11.136.0.5; WHM: 11.40.0.0 < 11.86.0.41, 11.88.0.0 < 11.94.0.28, 11.96.0.0 < 11.102.0.39, 11.104.0.0 < 11.110.0.97, 11.112.0.0 < 11.118.0.63, 11.120.0.0 < 11.124.0.35, 11.126.0.0 < 11.126.0.54, 11.128.0.0 < 11.130.0.19, 11.132.0.0 < 11.132.0.29, 11.134.0.0 < 11.134.0.20, 11.136.0.0 < 11.136.0.5 · Fixed: WP Squared: 11.136.1.7
    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-2026-26246↗CISA KEV record↗CVE authority or vendor reference↗Public exploit reference↗Public exploit 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-2026-41940 · cve.blacktree.nl