CVE-2026-77159

MEDIUMCVSS 5.5/10EPSS 0.16%

Last modified

CVE-2026-77159 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.16%

5.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Red HatRed Hat Enterprise Linux 10All versions
Red HatRed Hat Enterprise Linux 7All versions
Red HatRed Hat Enterprise Linux 8All versions
Red HatRed Hat Enterprise Linux 9All versions

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-77159?
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.
How severe is CVE-2026-77159?
CVE-2026-77159 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2026-77159?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST