CVE-2026-19816
Publication date 14 September 2026
Last updated 24 September 2026
Ubuntu priority
Description
A flaw was found in PackageKit. PackageKit skips the polkit authorization check for transactions carrying the SIMULATE (dry-run) flag. In the dnf5 backend, the RepoRemove handler ignores that contract and always executes the real transaction because its guard is written as (role == REPO_REMOVE || !SIMULATE), which is always true for RepoRemove. An unprivileged local user can therefore perform a genuine package uninstall while claiming to simulate. This vulnerability only affects systems using PackageKit with the dnf5 backend.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| packagekit | 26.04 LTS resolute |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
Notes
john-breton
Only affects the dnf5 backend, which was introduced upstream in 1.3.x. Ubuntu builds PackageKit with only the apt backend (-Dpackaging_backend=apt), so the vulnerable dnf5 code is not compiled in releases whose source contains it. The apt backend's RepoRemove correctly honours the SIMULATE flag.
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.1 · High
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H