CVE-2026-93834

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-25. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.8Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user.

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
56
EG Risk 56/100CISA SSVC

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
Severity88% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
29th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 29, 2026

Advisory Details (3)

Auto-updated Sep 25, 2026
Patch available. Sources: redhat.
generic

VM guest escape via 9p filesystem exploit (#4491) · Issues · QEMU / QEMU · GitLab

https://gitlab.com/qemu-project/qemu/-/work_items/4491
redhat

2537939 – (CVE-2026-93834) CVE-2026-93834 qemu-kvm: 9pfs: use-after-free race in Tlcreate/Twalk allows VM guest escape

https://bugzilla.redhat.com/show_bug.cgi?id=2537939
redhat Patch Available

CVE-2026-93834 - 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-2026-93834

Vendor Advisories for CVE-2026-93834(2)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.0+ds-1 ... 1:9.2.2+ds-1~bpo12+1 (200 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.10+ds-0+deb13u1 ... 1:11.1.2+ds-1 (67 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.2+ds-2 ... 1:11.1.2+ds-1 (57 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 37× in last 7d / 51× 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. 2026-10-05 05:54 UTCEG score recompute
  2. 2026-10-05 05:54 UTCVendor advisory
  3. 2026-10-05 05:54 UTCGHSA enrichment
  4. 2026-10-04 23:23 UTCEPSS rescore
  5. 2026-10-04 18:16 UTCVendor advisory
  6. 2026-10-04 18:16 UTCGHSA enrichment
  7. 2026-10-04 06:41 UTCVendor advisory
  8. 2026-10-04 06:41 UTCGHSA enrichment
  9. 2026-10-03 19:07 UTCEG score recompute
  10. 2026-10-03 19:07 UTCVendor advisory
  11. 2026-10-03 19:07 UTCGHSA enrichment
  12. 2026-10-03 14:26 UTCEPSS rescore
  13. 2026-10-03 07:32 UTCVendor advisory
  14. 2026-10-03 07:31 UTCGHSA enrichment
  15. 2026-10-02 19:54 UTCEG score recompute
  16. 2026-10-02 19:54 UTCVendor advisory
  17. 2026-10-02 19:54 UTCGHSA enrichment
  18. 2026-10-02 08:19 UTCVendor advisory
  19. 2026-10-02 08:19 UTCGHSA enrichment
  20. 2026-10-01 20:44 UTCEG score recompute
  21. 2026-10-01 20:44 UTCVendor advisory
  22. 2026-10-01 20:44 UTCGHSA enrichment
  23. 2026-10-01 19:51 UTCEPSS rescore
  24. 2026-10-01 09:09 UTCVendor advisory
  25. 2026-10-01 09:09 UTCGHSA enrichment
Show 26 more
  1. 2026-09-30 21:34 UTCEG score recompute
  2. 2026-09-30 21:34 UTCGHSA enrichment
  3. 2026-09-30 15:04 UTCEPSS rescore
  4. 2026-09-30 09:52 UTCGHSA enrichment
  5. 2026-09-29 22:18 UTCEG score recompute
  6. 2026-09-29 22:17 UTCGHSA enrichment
  7. 2026-09-29 11:26 UTCGHSA enrichment
  8. 2026-09-28 23:51 UTCEG score recompute
  9. 2026-09-28 23:51 UTCGHSA enrichment
  10. 2026-09-28 13:52 UTCEPSS rescore
  11. 2026-09-28 13:52 UTCEPSS rescore
  12. 2026-09-28 12:16 UTCGHSA enrichment
  13. 2026-09-28 00:41 UTCEG score recompute
  14. 2026-09-28 00:41 UTCGHSA enrichment
  15. 2026-09-27 13:49 UTCEPSS rescore
  16. 2026-09-27 13:06 UTCGHSA enrichment
  17. 2026-09-27 01:31 UTCEG score recompute
  18. 2026-09-27 01:31 UTCGHSA enrichment
  19. 2026-09-26 15:59 UTCEPSS rescore
  20. 2026-09-26 13:54 UTCGHSA enrichment
  21. 2026-09-26 02:01 UTCEG score recompute
  22. 2026-09-26 02:01 UTCGHSA enrichment
  23. 2026-09-25 14:22 UTCEG score recompute
  24. 2026-09-25 14:04 UTCEG score recompute
  25. 2026-09-25 13:44 UTCEG score recompute
  26. 2026-09-25 13:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-93834?
CVE-2026-93834 is a high vulnerability published on September 25, 2026. A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal…
When was CVE-2026-93834 disclosed?
CVE-2026-93834 was first published on September 25, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-93834 actively exploited?
CVE-2026-93834 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (29th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93834?
CVE-2026-93834 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-93834?
A fix for CVE-2026-93834 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-93834 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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