What’s Vulnerable › Vulnerabilities

CVE-2026-77159: Libvirt: unsafe chown in qemutpmemulatorpreparehost() allows arbitrary file ownership change via symlink

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-11 · updated 2026-09-16
• Weakness: CWE-61

Description

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.

Affected products

• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-77159
• https://bugzilla.redhat.com/show_bug.cgi?id=2531811
• https://gitlab.com/libvirt/libvirt/-/work_items/909
• https://gitlab.com/libvirt/libvirt/-/work_items/909

Get alerted when CVE-2026-77159 or the next vulnerability affects your stack