CVE-2026-12080: Qemu-kvm: qemu-guest-agent: local privilege escalation via symlink attack in guest-ssh-add-authorized-keys
A flaw was found in the QEMU Guest Agent (qga). A local unprivileged user can exploit a vulnerability in the guest-ssh-add-authorized-keys command handler by manipulating symbolic links. This can occur either through a deterministic directory-symlink bypass or a Time-of-Check to Time-of-Use (TOCTOU) file-symlink race. Successful exploitation allows the attacker to gain ownership of arbitrary root-owned files or directories, leading to root access. This vulnerability requires an external management layer (e.g., libvirt) to trigger the affected code path.
Other sources
Qemu-kvm: qemu-guest-agent: local privilege escalation via symlink attack in guest-ssh-add-authorized-keys
— Microsoft
When qmpguestsshaddauthorizedkeys adds an SSH key for an existing local user, the agent (running as root) decides whether to create the user's .ssh directory with a symlink-following directory test, and then writes and chowns the authorizedkeys file using a plain chown (not lchown). A local unprivileged user who owns their home directory can pre-stage their .ssh directory (or the authorizedkeys file) as a symbolic link so that, when the host or operator triggers a key add for that user, the root agent follows the link and transfers ownership of an arbitrary root-owned file or directory to the unprivileged user, who can then rewrite it to obtain root.
Patch: https://patchew.org/QEMU/20260709105707.91209-1-kkostiuk@redhat.com/
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-12080?
The severity of CVE-2026-12080 is rated high with a score of 7.3.
What is the risk associated with CVE-2026-12080?
CVE-2026-12080 has a risk score of 64.
How do I fix CVE-2026-12080?
To mitigate CVE-2026-12080, update to the latest version of the QEMU Guest Agent that includes the security fix.
Who can be affected by CVE-2026-12080?
CVE-2026-12080 can be exploited by local unprivileged users who have access to the guest-ssh-add-authorized-keys command.
What kind of attack does CVE-2026-12080 enable?
CVE-2026-12080 allows for local privilege escalation via a symlink attack.