# CVE-2026-41940: WebPros cPanel & WHM and WP2 (WordPress Squared) Missing Authentication for Critical Function Vulnerability

- Exploited (CISA KEV): yes, added 2026-04-30, known ransomware use
- Published: 2026-04-29
- CVSS: 9.3 CRITICAL (v4.0)
- EPSS: 98.5% (100th percentile)
- CWE: CWE-306

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.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2026-04-30 | 1 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-07-07 | 69 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-04-30 · new · rule fb29b1b660864285a5ebac86eb2b9e2f · default Block
  > cPanel - Auth Bypass - CVE:CVE-2026-41940. Previous action: N/A. New action: Block. This is a new detection.
  Source: https://developers.cloudflare.com/changelog/post/2026-04-30-emergency-waf-release/

### F5

- 2026-07-07 · new · rule 200013184
  > Added: signature 200013184 "cPanel and WHM Authentication Bypass" (Authentication/Authorization Attacks, risk High), systems: Other Web Server. References: CVE-2026-41940.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 4 requests blocked), template CVE-2026-41940, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 4 requests blocked), template CVE-2026-41940, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2026-41940 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-41940