CVE-2026-88924
Publication date 10 September 2026
Last updated 1 October 2026
Ubuntu priority
Description
A flaw was found in the admin backend of gvfs. The privileged gvfsd-admin daemon changes the ownership of newly created private D-Bus sockets by calling the link-following chown() function on a pathname inside a user-controlled directory. A local attacker can exploit this via a Time-of-Check Time-of-Use (TOCTOU) race condition and exchange the socket pathname with a symbolic link pointing to an arbitrary root-owned file (such as /etc/pam.d/su). The daemon subsequently follows the symlink and changes the ownership of the targeted root-owned file to the attacker's user ID. This allows an authenticated local attacker to modify critical system files, leading to a full local privilege escalation to root.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| gvfs | 26.04 LTS resolute |
Fixed 1.60.0-1ubuntu0.1
|
| 24.04 LTS noble |
Fixed 1.54.4-0ubuntu1~24.04.4
|
|
| 22.04 LTS jammy |
Fixed 1.48.2-0ubuntu1.2
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.0 · High
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8845-1
- GVfs vulnerabilities
- 30 September 2026