Libvirt: unsafe chown in qemutpmemulatorpreparehost() allows arbitrary file ownership change via symlink

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-77159
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-11 11:16:54 UTC
Updated2026-09-11 11:16:54 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS: 0.001620000 probability, percentile 0.057460000 (date 2026-09-12)

Problem Types: CWE-61 | CWE-61 UNIX Symbolic Link (Symlink) Following

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
3.1CNACVSS5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 6 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 9 Not specified Not specified

References

ReferenceSourceLinkTags
gitlab.com/libvirt/libvirt/-/work_items/909 [email protected] gitlab.com
access.redhat.com/security/cve/CVE-2026-77159 [email protected] access.redhat.com
bugzilla.redhat.com/show_bug.cgi [email protected] bugzilla.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank Suraj Theekshana for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-09-11T00:00:00.000ZReported to Red Hat.
CNA2026-09-11T00:00:00.000ZMade public.

Workarounds

CNA: On Red Hat Enterprise Linux, SELinux in enforcing mode (the default) confines the swtpm process to the swtpm_t domain, which restricts the creation of symlinks to arbitrary file types and limits the scope of any ownership change, reducing the practical impact of this flaw. Ensure SELinux is not disabled or set to permissive mode.

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report