Auth bypass in Fedora
CVE-2026-19816
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.
Vulnerability class: Broken Access Control
CVSS v3 metric
CVSS v3 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.
Affected products
Weakness classification (CWE)
References
- patrick@puiterwijk.org (issue-tracking)
- patrick@puiterwijk.org (patch)
- patrick@puiterwijk.org (vendor-advisory)
Frequently asked questions
- What is CVE-2026-19816?
- CVE-2026-19816 is a high-severity vulnerability in Fedora, classified under Incorrect Authorization. CVSS score: 7.1/10. Published 2026-09-14.
- How severe is CVE-2026-19816?
- High severity. CVSS v3 base score is 7.1 out of 10.