Auth bypass in Cpanel
CVE-2026-41940
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.985 (99.9th percentile), scored .
Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 99.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.985 · newest: 0.985 · change: 0.000
Affected products
- Cpanel
- Cpanel Whm
- Cpanel Wp Squared
- Webpros Cpanel — versions 11.104.0.0, 11.112.0.0, 11.120.0.0
- Webpros Whm — versions 11.104.0.0, 11.112.0.0, 11.120.0.0
- Webpros Wp Squared — versions 11.136.1.7
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Known ransomware campaign use: yes.
Public proof-of-concept exploits
References
- support.cpanel.net/hc/en-us/articles/40073787579671-cPanel-WHM-Security-Update-… (vendor-advisory, patch, Vendor Advisory)
- docs.cpanel.net/release-notes/release-notes (release-notes, Release Notes)
- docs.wpsquared.com/changelogs/versions/changelog/ (release-notes, Release Notes)
- www.namecheap.com/status-updates/ongoing-critical-security-vulnerability-in-cpa… (Third Party Advisory, third-party-advisory)
- www.vulncheck.com/advisories/cpanel-and-whm-authentication-bypass-via-login-flow (Third Party Advisory, third-party-advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Exploit, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Press/Media Coverage)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Exploit, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2026-41940?
- CVE-2026-41940 is a critical-severity vulnerability in Cpanel, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-04-29.
- How severe is CVE-2026-41940?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-41940 known to be exploited?
- Yes. CVE-2026-41940 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-30), indicating it is being actively exploited. 100 public proof-of-concept repositories are indexed.