Threat Intelligence / CVE / CVE-2026-41940

CVE-2026-41940 — Cpanel

CISA KEV

CVSS v3.1 9.8 (CRITICAL) · CVSS v4.0 9.3 · EPSS 28.3% (higher than 96.5% of all scored CVEs) · Priority 9/10 · Published 2026-04-29

As of 2026-04-30, CVE-2026-41940 is a CRITICAL-severity vulnerability in Cpanel, CVSS v3.1 9.8, EPSS 28.3% (96.5th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-30), with a US federal remediation deadline of 2026-05-03. Threadlinqs Intelligence links 4 tracked threat campaigns to CVE-2026-41940, most recently “Compromised Packagist PHP Packages Weaponize GitHub Actions Runners to Target cPanel/WHM Servers (CVE-2026-41940)”.

Last updated: 2026-04-30

What is 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.

The record classifies CVE-2026-41940 under weakness class CWE-306. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 136 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 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 base score: 9.3
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 (FIRST): 28.3% probability of exploitation in the next 30 days, higher than 96.5% of all scored CVEs
CISA KEV: Listed since 2026-04-30, federal remediation deadline 2026-05-03
Threadlinqs priority: 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published: 2026-04-29, last modified 2026-04-30

Is CVE-2026-41940 being exploited?

CISA added CVE-2026-41940 to the Known Exploited Vulnerabilities catalog on 2026-04-30, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-05-03 under BOD 22-01. It currently carries a trending score of 34 in the Threadlinqs vulnerability feed.

Affected products and versions

Cpanel: Cpanel, Whm

How to fix CVE-2026-41940

The record marks a vendor fix as available for CVE-2026-41940. Vendor advisory: https://support.cpanel.net/hc/en-us/articles/40073787579671-cPanel-WHM-Security-Update-04-28-2026. Because CVE-2026-41940 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-05-03. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-41940

4 tracked threats in the Threadlinqs corpus reference CVE-2026-41940, either in the campaign’s CVE list or as an indicator on the campaign record.

Compromised Packagist PHP Packages Weaponize GitHub Actions Runners to Target cPanel/WHM Servers (CVE-2026-41940) — CRITICAL · 2026-07-25
KryBit Ransomware-as-a-Service Strikes Back — Breaches 0APT Infrastructure Amid Faux-Ransomware Feud (May 2026) — HIGH · 2026-05-13
Sorry Ransomware Mass Exploitation of cPanel/WHM Authentication Bypass CVE-2026-41940 (44,000+ Servers Compromised) — CRITICAL · 2026-05-02
cPanel & WHM Missing Authentication for Critical Function (CVE-2026-41940) — CISA KEV — CRITICAL · 2026-04-30

Sources

Seeded from nvd and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-41940 are available via the Threadlinqs MCP server (Purple tier). View plans →

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