CyberSecBulletin
CVE-2026-41940Exploited in the wildNVD status: Analyzed

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

Published Updated By the CyberSecBulletin desk

CVE-2026-41940 is a critical-severity missing authentication for critical functionality vulnerability in cPanel from WebPros, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 11.86.0.41, 11.94.0.28, 11.102.0.39 as the first without the flaw, so updating cPanel to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on April 30, 2026, which means attacks have been observed in the wild, including in ransomware campaigns.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update cPanel to 11.86.0.41 or 11.94.0.28 or 11.102.0.39 or 11.110.0.97, whichever matches your release line, or a later version.
  2. Update WP Squared to 11.136.1.7 or a later version.
  3. Update WHM to 11.86.0.41 or 11.94.0.28 or 11.102.0.39 or 11.110.0.97, whichever matches your release line, or a later version.
  4. CISA's 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.
  5. Read the advisory on support.cpanel.net for workarounds and exact fixed builds.
  6. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
WebProscPanel11.40.0.0 up to, but not including, 11.86.0.41; 11.88.0.0 up to, but not including, 11.94.0.28; 11.96.0.0 up to, but not including, 11.102.0.39; 11.104.0.0 up to, but not including, 11.110.0.97; 11.112.0.0 up to, but not including, 11.118.0.63; 11.120.0.0 up to, but not including, 11.124.0.35; 11.126.0.0 up to, but not including, 11.126.0.54; 11.128.0.0 up to, but not including, 11.130.0.19; and 3 more ranges11.86.0.41, 11.94.0.28, 11.102.0.39, 11.110.0.97, 11.118.0.63, 11.124.0.35
WebProsWP Squaredbefore 11.136.1.711.136.1.7
WebProsWHM11.40.0.0 up to, but not including, 11.86.0.41; 11.88.0.0 up to, but not including, 11.94.0.28; 11.96.0.0 up to, but not including, 11.102.0.39; 11.104.0.0 up to, but not including, 11.110.0.97; 11.112.0.0 up to, but not including, 11.118.0.63; 11.120.0.0 up to, but not including, 11.124.0.35; 11.126.0.0 up to, but not including, 11.126.0.54; 11.128.0.0 up to, but not including, 11.130.0.19; and 3 more ranges11.86.0.41, 11.94.0.28, 11.102.0.39, 11.110.0.97, 11.118.0.63, 11.124.0.35

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).

Scoring systemScoreSeverityScored by
CVSS 4.09.3CriticalCNA (vulncheck.com)
CVSS 3.19.8CriticalCNA (vulncheck.com)

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Authentication for Critical Functionality

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.

More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
  3. Added to CISA's Known Exploited Vulnerabilities catalogue.
  4. Deadline for US federal agencies to remediate, set by CISA.
  5. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in cPanel

All cPanel vulnerabilities

Recent Missing Authentication for Critical Functionality vulnerabilities

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