How severe is CVE-2026-41940?

CVE-2026-41940 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-41940?

Affected package information for CVE-2026-41940 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-41940?

No fixed version has been published for CVE-2026-41940 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2026-41940 actively exploited in the wild?

Yes. There are 8 known exploit references for CVE-2026-41940, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-41940?

CVE-2026-41940 has an EPSS (Exploit Prediction Scoring System) score of 90.3%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2026-41940 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2026-41940 (WebPros cPanel & WHM and WP2 (WordPress Squared) Missing Authentication for Critical Function Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-04-30. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-05-03. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2026-41940?

CVE-2026-41940 is classified as Missing Authentication (CWE-306). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2026-41940?

CVE-2026-41940 affects cpanel cpanel; cpanel whm; cpanel wp squared. Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2026-41940?

A Nuclei detection template exists for CVE-2026-41940, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2026-41940 published, and has it been updated?

CVE-2026-41940 was published on April 29, 2026 and was last updated on May 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2026-04-30 — agencies required to remediate by 2026-05-03 · Ransomware

CVE-2026-41940

CRITICAL

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.

Published

Apr 29, 2026

Updated

May 4, 2026

Affected

0 pkgs

Patched

None yet

Exploits

8 known

EPSS Exploitation Probability

via FIRST.org ↗

90.3%probability of exploitation in next 30 days

Very High Risk100th percentile-0.42%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Affected Products

3 products · 19 configurations

Application

cpanelcpanel

≥ 136.0.0 && < 136.0.5

range

Application

whmcpanel

≥ 136.0.0 && < 136.0.5

range

Application

wp squaredcpanel

< 136.1.7

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-52574webappsphp

cPanel - CRLF Injection

by nu11secur1ty · May 26, 2026

Exploit-DB Source

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2026-41940 in your stack?

O3 detects CVE-2026-41940 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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