cPanel ConfigServer Security & Firewall Vulnerability Allows Remote Attacker to Execute Arbitrary Commands
CSF 14.00–16.29 (CVE-2026-65638) lets unauthenticated attackers execute arbitrary commands via the MESSENGER service on cPanel/WHM servers; version 16.30 fixes it.
CVE-2026-65638 affects ConfigServer Security & Firewall (CSF) versions 14.00 through 16.29 and allows unauthenticated remote attackers to execute arbitrary commands through the MESSENGER service, running under the unprivileged CSF service account rather than root. Exploitation requires the non-default MESSENGER service to be enabled and a reCAPTCHA secret configured, reducing exposure for standard deployments. CSF 16.30 and later fix the flaw; administrators who cannot update immediately can set MESSENGER = 0 in /etc/csf/csf.conf as a temporary mitigation.
LiteSpeed Enterprise Flaw Could Let One Hosting Account Gain Root Access on a Shared Server
cPanel warns critical LiteSpeed Web Server Enterprise flaw (pre-6.3.7) lets shared-hosting account users gain root access.
A cPanel advisory published September 14 warns that a critical vulnerability in LiteSpeed Web Server Enterprise versions before 6.3.7 lets a low-privilege website user gain root access on shared-hosting servers, bypassing CageFS account isolation. LiteSpeed released version 6.3.7 on September 11, but auto-update may be delayed so admins should force the update manually. No CVE identifier, severity score, workaround, or exploitation information has been published. This is the third LiteSpeed root flaw since May, following CVE-2026-48172 and CVE-2026-54420 in the cPanel plugin, which were both actively exploited and added to CISA's KEV catalog.
cPanel LiteSpeed Web Server Vulnerability Allows Shared Server Users to Gain Root-Level Access
Critical LiteSpeed Enterprise flaw fixed in 6.3.7 lets low-privilege shared-hosting users escalate to root and bypass CageFS.
cPanel issued an urgent advisory for a critical privilege escalation in LiteSpeed Web Server Enterprise versions before 6.3.7, allowing a low-privilege shared-hosting account to gain root-level server control and bypass tenant isolation controls including CloudLinux CageFS. Root access would let attackers access other hosted sites, steal databases and credentials, deploy phishing pages, and install backdoors. Administrators are urged to upgrade to 6.3.7 immediately via lsup.sh and to review privileged account activity, cron jobs, SSH keys, and system binaries; no CVE identifier was published.
Critical cPanel Flaw Could Let One Hosting Customer Take Root Control of a Whole Server
cPanel patched critical flaw CVE-2026-65643 letting authenticated hosting customers with addon or parked domain rights execute code as root and fully compromise servers.
cPanel issued patches on August 27, 2026 for CVE-2026-65643, a flaw in domain parking and addon domain functionality in cPanel & WHM that lets an authenticated account holder create arbitrary files and execute code as root, yielding full server control. Fixed builds cover the 11.110, 11.134, 11.136 and 11.138 branches, including WP Squared 11.138.1.7, and auto-update servers receive the fix automatically. No CVSS score, published CVE record, or evidence of exploitation has appeared, and the flaw is absent from CISA's KEV catalog as of August 27. The article also recaps related 2026 cPanel-ecosystem issues, including KEV-listed LiteSpeed plugin flaws and the in-the-wild-exploited Phusion Passenger problem.