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CVE-2026-41940

critical

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.

References

https://www.vulncheck.com/advisories/cpanel-and-whm-authentication-bypass-via-login-flow

https://www.namecheap.com/status-updates/ongoing-critical-security-vulnerability-in-cpanel-april-28-2026

https://support.cpanel.net/hc/en-us/articles/40073787579671-cPanel-WHM-Security-Update-04-28-2026

https://securityaffairs.com/192013/cyber-crime/attackers-exploit-cpanel-cve-2026-41940-to-deploy-filemanager-backdoor.html

https://thehackernews.com/2026/05/cpanel-cve-2026-41940-under-active.html

https://securityaffairs.com/191931/security/new-cpanel-vulnerabilities-could-allow-file-access-and-remote-code-execution.html

https://thehackernews.com/2026/05/cpanel-whm-patch-3-new-vulnerabilities.html

https://www.itsecurityguru.org/2026/05/08/pentest-tools-com-releases-free-scanner-for-cve-2026-41940-as-cpanel-authentication-bypass-enters-its-third-week-of-active-exploitation/?utm_source=rss&utm_medium=rss&utm_campaign=pentest-tools-com-releases-free-scanner-for-cve-2026-41940-as-cpanel-authentication-bypass-enters-its-third-week-of-active-exploitation

https://www.securityweek.com/over-40000-servers-compromised-in-ongoing-cpanel-exploitation/

https://www.darkreading.com/threat-intelligence/exploit-cyber-frenzy-critical-cpanel-vulnerability

https://securityaffairs.com/191613/hacking/u-s-cisa-adds-a-flaw-in-webpros-cpanel-to-its-known-exploited-vulnerabilities-catalog.html

https://www.bleepingcomputer.com/news/security/critrical-cpanel-flaw-mass-exploited-in-sorry-ransomware-attacks/

https://www.theregister.com/security/2026/05/01/critical-cpanel-exploited-millions-of-sites-could-be-hit/5225588

https://www.theregister.com/2026/05/01/critical_cpanel_vuln_hits_cisa/

https://www.malwarebytes.com/blog/news/2026/05/actively-exploited-cpanel-bug-exposes-millions-of-websites-to-takeover

https://www.databreachtoday.com/attacks-surge-against-vulnerable-cpanel-whm-software-a-31571

https://therecord.media/cisa-orders-federal-agencies-to-patch-cpanel-bug

https://www.theregister.com/security/2026/04/30/critical-cpanel-whm-flaw-probs-exploited-as-0-day-pros-say/5228744

https://www.theregister.com/2026/04/30/cpanel_whn_cves/

https://www.securityweek.com/critical-cpanel-whm-vulnerability-exploited-as-zero-day-for-months/

https://www.helpnetsecurity.com/2026/04/30/cpanel-zero-day-vulnerability-cve-2026-41940-exploited/

https://www.cisa.gov/news-events/alerts/2026/04/30/cisa-adds-one-known-exploited-vulnerability-catalog

https://www.bleepingcomputer.com/news/security/critical-cpanel-and-whm-bug-exploited-as-a-zero-day-poc-now-available/

https://cyberscoop.com/cpanel-authentication-bypass-vulnerability-cve-2026-41940-exploited/

https://arcticwolf.com/resources/blog/cve-2026-41940/

https://www.bleepingcomputer.com/news/security/cpanel-whm-emergency-update-fixes-critical-auth-bypass-bug/

https://thehackernews.com/2026/04/critical-cpanel-authentication.html

https://labs.watchtowr.com/the-internet-is-falling-down-falling-down-falling-down-cpanel-whm-authentication-bypass-cve-2026-41940/

https://slcyber.io/research-center/new-age-of-collisions-reading-arbitrary-files-pre-auth-as-root-in-cpanel-cve-2026-29205/

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-41940

https://docs.wpsquared.com/changelogs/versions/changelog/#13617

https://docs.cpanel.net/release-notes/release-notes

Details

Source: Mitre, NVD

Published: 2026-04-29

Updated: 2026-05-04

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

CVSS v4

Base Score: 9.3

Vector: 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

Severity: Critical

EPSS

EPSS: 0.88634

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Interest