CVE-2026-77159

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH confidence

Score 5.5 from GitHub Security Advisory published 2026-09-11. a secondary CVSS source baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.5
EG Score
5.5(high)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

September 11, 2026

Last Modified

September 16, 2026

Advisory Details (3)

Auto-updated Sep 11, 2026
Patch available. Sources: redhat.
generic

Unsafe chown in qemuTPMEmulatorPrepareHost() allows arbitrary file ownership transfer via symlink (#909) · Issues · libvirt / libvirt · GitLab

https://gitlab.com/libvirt/libvirt/-/work_items/909
redhat

2531811 – (CVE-2026-77159) CVE-2026-77159 libvirt: Unsafe chown in qemuTPMEmulatorPrepareHost() allows arbitrary file ownership change via symlink

https://bugzilla.redhat.com/show_bug.cgi?id=2531811
redhat Patch Available

CVE-2026-77159 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-77159

Vendor Advisories for CVE-2026-77159(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 25× in last 7d / 28× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:15 UTCVendor advisory
  3. 2026-09-18 19:15 UTCGHSA enrichment
  4. 2026-09-17 19:43 UTCEG score recompute
  5. 2026-09-17 19:43 UTCVendor advisory
  6. 2026-09-17 19:43 UTCGHSA enrichment
  7. 2026-09-16 19:59 UTCGHSA enrichment
  8. 2026-09-16 16:05 UTCEG score recompute
  9. 2026-09-16 16:05 UTCGHSA enrichment
  10. 2026-09-16 14:08 UTCEPSS rescore
  11. 2026-09-16 05:15 UTCEPSS rescore
  12. 2026-09-15 16:34 UTCEG score recompute
  13. 2026-09-15 16:34 UTCGHSA enrichment
  14. 2026-09-15 15:44 UTCEG score recompute
  15. 2026-09-15 15:43 UTCGHSA enrichment
  16. 2026-09-15 09:32 UTCEG score recompute
  17. 2026-09-15 09:32 UTCGHSA enrichment
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-14 10:02 UTCEG score recompute
  20. 2026-09-14 10:02 UTCGHSA enrichment
  21. 2026-09-13 10:30 UTCEG score recompute
  22. 2026-09-13 10:30 UTCGHSA enrichment
  23. 2026-09-12 15:02 UTCEPSS rescore
  24. 2026-09-12 10:59 UTCEG score recompute
  25. 2026-09-12 10:59 UTCGHSA enrichment
Show 3 more
  1. 2026-09-11 11:26 UTCEG score recompute
  2. 2026-09-11 10:46 UTCEG score recompute
  3. 2026-09-11 10:44 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77159?
CVE-2026-77159 is a medium vulnerability published on September 11, 2026. 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…
When was CVE-2026-77159 disclosed?
CVE-2026-77159 was first published in the National Vulnerability Database on September 11, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77159 actively exploited?
CVE-2026-77159 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 94.1% of all scored CVEs.
What is the CVSS score of CVE-2026-77159?
CVE-2026-77159 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-77159?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77159, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-77159

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