CVE WatchCVE-2026-41940

CVE-2026-41940CVSS 9.8 · CRITICAL⚡ CISA KEV — Actively ExploitedPublished April 29, 2026

cPanel Authentication Bypass Allows Unauthenticated Control Panel Access

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.

Casky was already ahead

This CVE exploits attack patterns that Casky's 261matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

CVE-2026-41940 is a critical authentication bypass vulnerability in cPanel and WHM versions after 11.40 that permits unauthenticated remote attackers to gain full unauthorized access to hosting control panels. This vulnerability is particularly severe because cPanel/WHM instances manage thousands of websites, email accounts, and databases across hosting providers globally. Organizations running affected versions—especially shared hosting providers, resellers, and enterprises managing their own infrastructure—face immediate risk of complete account compromise, data theft, malware injection, and lateral movement into hosted customer environments. With a CVSS score of 9.8 and active exploitation confirmed in CISA's KEV catalog, this represents a "move fast or breach" scenario.

Casky's 261 matching security skills leverage Claude's extended reasoning to detect the attack patterns embedded in TA0004 (Privilege Escalation) and TA0006 (Credential Access) across your environment. Practitioners using Casky would identify suspicious patterns such as: successful login sessions originating from unexpected IP ranges without corresponding authentication credentials, rapid authentication attempts that bypass MFA controls, and lateral movement from the cPanel interface into hosted accounts or system directories. Claude's reasoning engine correlates these indicators—recognizing that legitimate administrators don't suddenly appear with valid sessions post-exploitation—and surfaces findings showing the initial authentication bypass footprint (CWE-306: Missing Authentication) alongside post-exploitation credential harvesting and privilege escalation activities. Your security team receives not just "authentication succeeded unexpectedly" alerts, but contextual narratives explaining the attack chain and which customers or systems require immediate remediation.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

261 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-41940.

analyzing-cloud-storage-access-patterns

cloud security · low

Run

analyzing-kubernetes-audit-logs

container security · low

Run

analyzing-malicious-url-with-urlscan

phishing defense · medium

Run

MITRE ATT&CK Techniques

TA0004 TA0006

Investigate the attack patterns behind CVE-2026-41940

Casky has 261 skills that investigate the attack patterns behind CVE-2026-41940. Run one and get CVSS-scored findings in 3 minutes.

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