WARNING--Parallels Desktop CVE-2026-90894 Gives Any Local User Root on a Mac; the Fix Is in Version 27, Which Intel Macs Cannot Install

A root service answers any local account

The flaw is CVE-2026-90894. The CVE record, published by JFrog on September 14, scores it 7.8, classes it as argument injection, and carries a CISA assessment of the same day that lists exploitation as "none". Parallels Desktop installs a helper, prl_disp_service, that runs as root and listens on a socket any process on the Mac can open. JFrog's Yuval Moravchick found that its local login accepts an unsigned program run by a non-admin user, and that its appliance installer builds a tar command around a folder name the caller supplies. A quotation mark in that name turns what follows into options for tar, and tar's --use-compress-program option then runs the attacker's script as root. No virtual machine has to be running.

This is not a remote attack: something must already be running on the Mac under an ordinary account. JFrog's examples are a malicious Homebrew formula, "a poisoned npm preinstall, or a browser download that lands as a local user", and one weak student account on a shared lab Mac. It adds: "From root, the attacker can replace system software, read other users' data, and persist via launchd."

Parallels has not named the bug, and the dates disagree

JFrog's timeline has the report going to Parallels on July 14 and the fix arriving "in Parallels Desktop 27.0.0" on September 1. Parallels' release notes for version 27 date 27.0.0 to August 25, 27.0.1 to September 1 and 27.0.2, build 58673, to September 17. The one security line under 27.0.0 covers "the virtual networking stack, virtual GPU command processing, and VirtIO subsystem"; the appliance installer is not in it, and no entry names the CVE. Parallels' list of security fixes says the company "does not disclose, confirm or discuss security vulnerabilities until they are fixed, and the fix has been released to the public"; the page was last reviewed on May 20, 2025, its newest row is a fix shipped on April 17, 2025, and this CVE is not on it. The Hacker News reported the mismatch on September 16; 27.0.2 postdates both dates.

Intel Macs and Macs on Ventura stay on version 26

Parallels' system requirements give version 27 two conditions: an Apple silicon chip and macOS Sonoma 14.7 or newer. On Ventura 13 and earlier the installer sets up an older version, and Parallels' August 25 press release calls 27 "designed exclusively for Apple silicon Macs". The same day, Parallels' note to Intel owners said version 26 "fully supports Intel-based Mac computers" and that they can "expect future security and maintenance updates."

None has come that names this bug. Parallels' release notes for version 26, as read on October 3, end at 26.4.2, build 57518, of September 8, whose only listed change is an Enterprise deployment fix. JFrog's proof was on Apple silicon and it reports no test on an Intel Mac, but JFrog's advisory lists every version below 27.0.0 as affected and says of the old line: "Hosts that stay on the 26.x line, including 26.4.2, do not have that extract change."

Two lines have been patched at once before: our August 2007 note on Virtual PC 6.1.2 and 7.0.3 recorded Microsoft closing the same memory-overwrite hole in versions 6 and 7. The processor news in our October 2004 item on Virtual PC 7 was that it would now run on the G5.

What to do now

JFrog's check is the About box for the version and one Terminal command for the socket, ls -l /var/run/prl_disp_service.socket. If the line it prints begins srwxrwxrwx and the version is "at or near 26.4.0", JFrog says to "assume exposure until you can confirm a patched build."

On an Apple silicon Mac running Sonoma 14.7 or newer, move to Parallels Desktop 27, whose newest build on October 3 was 27.0.2. On an Intel Mac, or a Mac held on Ventura, there was as of October 3 nothing to install; JFrog's advice until there is something is to "restrict local login on those Macs", which at home means no guest or shared accounts and care over what you run.

We have not run JFrog's steps or installed either version. Parallels told Intel owners on August 25 to expect security updates, and this is the first one it owes them. [Macs Only!]