CVE-2026-77159 is a vulnerability in Red Hat Enterprise Linux (RHEL)
Published on September 11, 2026
Libvirt: unsafe chown in qemutpmemulatorpreparehost() allows arbitrary file ownership change via symlink
A symlink-following flaw was found in libvirt's qemuTPMEmulatorPrepareHost() function. The function uses a path-based chown() on the swtpm logfile without checking for symbolic links. A local attacker with access to the swtpm account can replace the logfile with a symlink, causing libvirtd (running as root) to transfer ownership of an arbitrary file to the swtpm user.
Vulnerability Analysis
CVE-2026-77159 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is a Symlink following Vulnerability?
The software, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the software to operate on unauthorized files. A software system that allows UNIX symbolic links (symlink) as part of paths whether in internal code or through user input can allow an attacker to spoof the symbolic link and traverse the file system to unintended locations or access arbitrary files. The symbolic link can permit an attacker to read/write/corrupt a file that they originally did not have permissions to access.
CVE-2026-77159 has been classified to as a Symlink following vulnerability or weakness.
Products Associated with CVE-2026-77159
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