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cPanel released fixes for three vulnerabilities that break tenant isolation on shared-hosting servers. CVE-2026-87899 allows an authenticated cPanel account holder to escalate privileges and execute code as root, potentially taking control of the entire host; CVE-2026-68490 exposes other accounts’ CalDAV/CardDAV calendar events and contacts through incorrect permissions. Both affect cPanel & WHM version 120 and later.
A separate WP Toolkit vulnerability, CVE-2026-87900, enables a logged-in cPanel user to modify databases belonging to other cPanel accounts. cPanel has issued fixed builds, but no temporary mitigations were provided for the CalDAV/CardDAV issues and no exploitation has been reported. Administrators should urgently update cPanel/WHM and WP Toolkit, particularly on public multi-tenant deployments, and investigate anomalous cross-account access or database changes.
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3 events from the most recent confirmed update back to the earliest known activity.
On September 22, 2026, cPanel patched CVE-2026-87900 in WP Toolkit, which enables a logged-in cPanel user to modify databases belonging to other accounts. The flaw affects WP Toolkit 6.11.2-10794 and earlier and is remediated in version 6.11.3 or later.
On September 22, 2026, cPanel released a fix for CVE-2026-68490, an incorrect-permissions flaw allowing a local server user to read other accounts' calendar events and contacts. The vulnerability affects cPanel & WHM 120 and later but does not permit data modification or root access.
On September 22, 2026, cPanel disclosed CVE-2026-87899, which lets an authenticated cPanel account holder execute code as root through CalDAV/CardDAV. The issue affects cPanel & WHM 120 and later and was fixed in specified 11.134, 11.136, 11.138, and WP Squared builds.
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cPanel disclosed and patched a critical authentication bypass in cPanel & WHM, tracked as **`CVE-2026-41940`**, after reports of active in-the-wild exploitation against hosting infrastructure. The flaw affects authentication paths in supported versions and can let unauthenticated attackers reach administrative interfaces, forge authenticated sessions, and potentially gain control of hosted websites, databases, email accounts, and server configuration. Government and industry alerts warned that shared hosting environments face outsized risk because a single compromised server can expose many downstream customer sites, and some providers temporarily restricted cPanel and WHM login ports while applying fixes. Public technical analysis and a GitHub proof-of-concept described an exploit chain involving manipulated HTTP headers and session cookie handling to create forged privileged sessions, including possible root-level WHM access. Separately, cPanel also patched three additional vulnerabilities in cPanel & WHM and **WP Squared**—**`CVE-2026-29201`**, **`CVE-2026-29202`**, and **`CVE-2026-29203`**—that enable arbitrary file read through path traversal, Perl code injection leading to remote code execution, and denial-of-service via unsafe symlink handling. The most severe of the newly disclosed flaws, **`CVE-2026-29202`**, affects the `create_user` API and can allow arbitrary Perl code execution on the server, reinforcing calls for immediate upgrades, restricted access to management interfaces, and log review for suspicious authorization and cookie activity.
Jun 29, 2026
cPanel has patched **CVE-2026-65643**, a critical flaw in cPanel & WebHost Manager (WHM) domain-parking and addon-domain functionality. A low-privileged authenticated hosting account authorized to add parked or addon domains can create arbitrary files on the underlying server, potentially leading to code execution as `root` and full control of the host. The issue affects all supported cPanel & WHM release branches, with fixes issued for 11.110, 11.134, 11.136, and 11.138, including WP Squared. Shared and reseller-hosting operators should apply the relevant patched build immediately; systems on end-of-life branches must be upgraded to a supported release, and unpatched deployments should restrict parked- and addon-domain permissions. cPanel had not disclosed a CVSS score, detection guidance, interim mitigation, or confirmed in-the-wild exploitation.
Sep 1, 2026
WebPros cPanel disclosed and patched a critical authentication bypass flaw in **cPanel & WHM** and **WP Squared**, now tracked as `CVE-2026-41940` with a **CVSS 9.8** score. The bug affects all supported cPanel & WHM versions after `11.40` prior to fixed releases, and reporting indicates some unsupported versions are likely vulnerable as well. Researchers said the issue stems from improper session handling tied to a **CRLF injection** in the login flow, allowing unauthenticated remote attackers to poison session data and gain administrator or root-level access to exposed hosting control panels. cPanel released emergency updates across supported branches, published detection guidance, and advised administrators to force updates, restart `cpsrvd`, and investigate session files and logs for signs of compromise. Multiple sources reported the flaw was **actively exploited in the wild** before patches were issued, with hosting providers such as **Namecheap** and **KnownHost** taking emergency action by restricting access to management ports like `2083` and `2087` while deploying fixes. **CISA** added `CVE-2026-41940` to its **Known Exploited Vulnerabilities** catalog and ordered federal agencies to remediate quickly, while national cyber agencies in Canada, Austria, and Belgium also warned of the risk. Public technical analysis, proof-of-concept code, and exploit tooling released after disclosure increased the likelihood of broad opportunistic attacks against internet-exposed cPanel systems, which researchers estimated number in the hundreds of thousands to more than a million, raising the risk of website compromise, credential theft, ransomware, phishing, and multi-tenant hosting breaches.
Sep 3, 2026