CVE-2026-74859: Gnome-tweaks: path traversal in theme installer
Summary: Path traversal in theme installer Requirements to exploit: user installs malicious gnome-shell theme Component affected: ShellThemeInstallerTweak Version affected: All versions Patch available: Yes Version fixed (if any already): Not yet Upstream coordination: See issue report (below) CVSS (optional): Impact (optional): Embargo: No Acknowledgment: Zach Sylvester Steps to reproduce if available: see issue report Mitigation if available: do not use gnome-tweaks to install gnome-shell themes Original report: https://gitlab.gnome.org/GNOME/gnome-tweaks/-/issues/542
Other sources
The shell theme installer in gnome-tweaks extracts user-supplied ZIP archives without validating archive member paths. As a result, a crafted theme archive can write files outside ~/.themes by using ../ path traversal, absolute paths, or symlink entries.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Do not use gnome-tweaks to install GNOME Shell themes; the gnome-tweaks shell theme installer can extract crafted theme ZIP archives without validating archive member paths (path traversal via ../, absolute paths, or symlink entries).
Event History
Frequently Asked Questions
Who is exposed to this issue?
Users of gnome-tweaks are exposed when they use its ShellThemeInstallerTweak component to install a malicious GNOME Shell theme archive. Exploitation requires a local user with low privileges to interact with the installer.
What must an attacker provide to exploit the vulnerability?
The attacker needs to convince a user to install a crafted GNOME Shell theme ZIP archive through gnome-tweaks. The archive can contain ../ paths, absolute paths, or symlink entries that cause files to be written outside the intended ~/.themes directory.
Are all versions affected, and is a fixed version available?
All versions are listed as affected. A patch is available, but no fixed version is identified yet.
What can be done if a patch cannot be applied immediately?
Do not use gnome-tweaks to install GNOME Shell themes. Avoid installing untrusted or externally supplied theme ZIP archives through the affected installer.