Disclosed 8 September 2026 · all supported cPanel versions

    CVE-2026-67401: the cPanel bug that turns a mail user into root

    A SQL injection flaw in cPanel's EmailTrack lets someone who only holds an email account write arbitrary files, and finish as root.

    By Simon Bumford, Founder of EveryHost7 min read

    TL;DR

    cPanel disclosed CVE-2026-67401 on 8 September 2026. An authenticated cPanel account holder with mail privileges can create arbitrary files through EmailTrack, and cPanel states that successful exploitation leads to code execution as root. Every supported version of cPanel and WHM is affected. The patched builds are v11.110.0.143, v11.134.0.55, v11.136.0.39, v11.138.0.4 and WP2 v11.138.1.9. All 11 EveryHost cPanel servers were on v11.136.0.39 by 17:01 on the day of disclosure. If you are hosted elsewhere, go and read your build number now.

    What cPanel actually disclosed

    The advisory is short, and worth reading exactly as written rather than as summarised by anyone, us included. cPanel says that an authenticated cPanel account holder with mail-related privileges can create arbitrary files on the server through the EmailTrack functionality, and that successful exploitation leads to code execution as the root user, giving an attacker full control of the server.

    Note the shape of that sentence. It begins with something very ordinary, an email account, and ends with something total. The interesting part of this vulnerability is not the SQL injection itself. It is the distance the injection travels.

    IdentifierCVE-2026-67401
    ComponentEmailTrack, in cPanel and WHM
    AffectedAll supported versions
    Patched buildsv11.110.0.143, v11.134.0.55, v11.136.0.39, v11.138.0.4, WP2 v11.138.1.9
    RequiresAn authenticated account with mail privileges
    Ends inCode execution as root

    Credit for responsible disclosure goes to Ali Mustafa (rz1027) and abed1526.

    The distance from an email account to root

    mail userlowest privilegeEmailTrackSQL injectionarbitrary filewritten to diskrootfull controlone authenticated account, four steps, total compromise

    On a single-tenant server, needing an authenticated account is a real barrier. You control every account on the box, so the set of people who could start that chain is the set of people you already trust.

    On shared or reseller hosting it is not a barrier at all. Every customer on the machine already holds an account with mail privileges. That is what they bought. So the question stops being "could an attacker get an account" and becomes "are all several hundred accounts on this server, and everyone who has ever reused one of those passwords elsewhere, trustworthy and uncompromised". One weak password on one unrelated site is the whole chain.

    This is the part worth sitting with if you run a Magento store on shared hosting. Your store's security is not a function of your own diligence. It is a function of the least careful tenant on the same machine.

    "All supported versions" means you too

    Some advisories affect one release line, and most readers can scroll to the table, see a version they are not running, and move on. This is not one of those. The affected column reads "All supported versions", which means being current was no protection. Diligence did not exempt anyone here. Patching after the fact was the only option available.

    That also means there is exactly one question that matters, and it is not whether your host takes security seriously in general. It is what build number your server is running right now. Everything else is atmosphere.

    One honest observation. cPanel's advisory publishes no CVSS score and no severity rating, which is unusual for a bug whose stated impact is root code execution. We are not going to invent a number to fill the gap. Judge it on the advisory's own words: low-privilege access in, full control of the server out.

    What we did, with timestamps

    Every cPanel server we run was affected, because every supported version was affected. We are not going to dress that up. What matters is the gap between disclosure and remediation, so here is ours, measured rather than asserted.

    All 11 EveryHost cPanel servers were running the patched build v11.136.0.39 on 8 September 2026, the same day the advisory went out. The first landed at 15:10 and the last at 17:01, a window of one hour and fifty one minutes. We then checked the running build on each server individually, because "the updater ran" and "the server is patched" are not the same claim.

    15:0016:0017:0011 of 11 servers patched, 15:10 to 17:01, day of disclosureeach dot is one server taking build v11.136.0.39

    If you are hosted somewhere else

    Do this today rather than adding it to a list. If you have root, run:

    /usr/local/cpanel/cpanel -V

    Compare the result against the patched build for your tier. A server on the 11.136 line needs build 39 or higher. If you cannot get a shell, WHM shows the running version on its home screen.

    If you are on shared hosting, ask your host for the exact build number. Not "are we patched", which invites a reassuring yes. Ask them to tell you the number and the time it was applied. A host that can answer that in minutes is telling you something useful about how the next one will go. A host that cannot, or will not, is also telling you something useful.

    Then look for what the bug actually does, which is create files. Anything unexpected and recently written under web-accessible paths deserves attention, which is the same instinct we wrote about when a genuine injection turned up during the StyleSmuggler sweep. And if you are heading into peak trading on a platform you are unsure about, the peak season security guide covers what to lock down before the code freeze.

    Frequently Asked Questions

    CVE-2026-67401 is a SQL injection vulnerability in the EmailTrack functionality of cPanel and WHM, disclosed by cPanel on 8 September 2026. cPanel's advisory states that an authenticated cPanel account holder with mail-related privileges can create arbitrary files on the server, and that successful exploitation leads to code execution as the root user, giving an attacker full control of the server.

    All supported versions of cPanel and WHM are affected. cPanel published patched builds v11.110.0.143, v11.134.0.55, v11.136.0.39 and v11.138.0.4, plus v11.138.1.9 for WP2. If your server is on a build lower than the patched build for its release tier, it is vulnerable.

    Run '/usr/local/cpanel/cpanel -V' as root on the server, or check WHM's home screen, which shows the running version. Compare it against the patched build for your tier. For example a server on the 11.136 tier needs build 39 or higher. If you cannot get a shell, ask your host to confirm the exact build number rather than a general assurance that the server is up to date.

    Yes, the advisory describes an authenticated cPanel account holder with mail-related privileges. That sounds like a high bar and on a single-tenant server it is. On a shared or reseller server it is not, because every hosting customer on that machine already holds exactly that kind of account. One compromised or malicious mail user on a box with hundreds of accounts is enough to reach root, and from root, every other site on the server.

    cPanel's advisory does not publish a CVSS score or a severity rating for this issue, which is unusual for a bug that ends in root code execution. We are not going to invent one. Judge it on what the advisory actually says: low-privilege access in, full control of the server out.

    Every cPanel server we run was affected, because all supported versions were affected. All 11 of our cPanel servers were updated to v11.136.0.39 on 8 September 2026, the day the advisory was published, between 15:10 and 17:01 UK time. We verified the running build on each server individually rather than assuming the update ran.

    Confirm your build number today, not your host's general reassurance. If it is behind, update cPanel or ask your host to. If you are on shared hosting and cannot get an answer within a few hours, treat that silence as information about how the next vulnerability will be handled too. Then check whether anything was created on the server that should not have been, because arbitrary file creation is the mechanism here.

    Source

    cPanel security advisory, CVE-2026-67401 SQL Injection Vulnerability in cPanel's EmailTrack Functionality, published 8 September 2026. Patch times in this article were read from the running build on each of our servers on the same day.

    Want a host that can tell you the build number?

    EveryHost runs dedicated and managed Magento servers in the UK, patched by UK engineers who will give you a timestamp rather than a reassurance. Ask us anything about this CVE, including whether your current setup is exposed.