WebPros cPanel and WHM Authentication Bypass via Login Flow
Summary
| CVE | CVE-2026-41940 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-29 16:16:25 UTC |
| Updated | 2026-05-04 18:09:42 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9.3 CRITICAL from [email protected]
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.905300000 probability, percentile 0.996270000 (date 2026-05-27)
CISA KEV: Listed on 2026-04-30; due 2026-05-03; ransomware use Known
Problem Types: CWE-306 | CWE-306 CWE-306 Missing Authentication for Critical Function
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.3 | CRITICAL | 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/E:X/C... |
| 4.0 | CNA | CVSS | 9.3 | CRITICAL | 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 |
| 3.1 | [email protected] | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known Exploited Vulnerability
| Vendor | WebPros |
|---|---|
| Product | cPanel & WHM and WP2 (WordPress Squared) |
| Name | WebPros cPanel & WHM and WP2 (WordPress Squared) Missing Authentication for Critical Function Vulnerability |
| Required Action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
| Notes | https://support.cpanel.net/hc/en-us/articles/40073787579671-cPanel-WHM-Security-Update-04-28-2026 ; https://docs.cpanel.net/release-notes/release-notes/ ; https://docs.wpsquared.com/changelogs/versions/changelog/#13617 ; https://nvd.nist.gov/vuln/detail/CVE-2026-41940" |
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | WebPros | CPanel | affected 11.40.0.0 11.86.0.41 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.88.0.0 11.110.0.97 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.112.0.0 11.118.0.63 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.120.0.0 11.124.0.35 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.125.0.0 11.126.0.54 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.128.0.0 11.130.0.19 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.132.0.0 11.132.0.29 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.134.0.0 11.134.0.20 custom | Not specified |
| CNA | WebPros | CPanel | affected 11.136.0.0 11.136.0.5 custom | Not specified |
| CNA | WebPros | WP Squared | unaffected 11.136.1.7 custom | Not specified |
| CNA | WebPros | WHM | affected 11.40.0.0 11.86.0.41 custom | Not specified |
| CNA | WebPros | WHM | affected 11.88.0.0 11.110.0.97 custom | Not specified |
| CNA | WebPros | WHM | affected 11.112.0.0 11.118.0.63 custom | Not specified |
| CNA | WebPros | WHM | affected 11.120.0.0 11.124.0.35 custom | Not specified |
| CNA | WebPros | WHM | affected 11.125.0.0 11.126.0.54 custom | Not specified |
| CNA | WebPros | WHM | affected 11.128.0.0 11.130.0.19 custom | Not specified |
| CNA | WebPros | WHM | affected 11.132.0.0 11.132.0.29 custom | Not specified |
| CNA | WebPros | WHM | affected 11.134.0.0 11.134.0.20 custom | Not specified |
| CNA | WebPros | WHM | affected 11.136.0.0 11.136.0.5 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.namecheap.com/status-updates/ongoing-critical-security-vulnerability-in-cpa... | [email protected] | www.namecheap.com | Third Party Advisory |
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | US Government Resource |
| github.com/watchtowrlabs/watchTowr-vs-cPanel-WHM-AuthBypass-to-RCE.py | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Exploit, Third Party Advisory |
| labs.watchtowr.com/the-internet-is-falling-down-falling-down-falling-down-cpanel... | af854a3a-2127-422b-91ae-364da2661108 | labs.watchtowr.com | Exploit, Third Party Advisory |
| www.vulncheck.com/advisories/cpanel-and-whm-authentication-bypass-via-login-flow | [email protected] | www.vulncheck.com | Third Party Advisory |
| support.cpanel.net/hc/en-us/articles/40073787579671-cPanel-WHM-Security-Update-0... | [email protected] | support.cpanel.net | Vendor Advisory |
| docs.wpsquared.com/changelogs/versions/changelog | [email protected] | docs.wpsquared.com | Release Notes |
| docs.cpanel.net/release-notes/release-notes | [email protected] | docs.cpanel.net | Release Notes |
| www.bleepingcomputer.com/news/security/critrical-cpanel-flaw-mass-exploited-in-sorry-r... | af854a3a-2127-422b-91ae-364da2661108 | www.bleepingcomputer.com | Press/Media Coverage |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-04-30T00:00:00.000Z | CVE-2026-41940 added to CISA KEV |
There are currently no legacy QID mappings associated with this CVE.