Bug 2537939 (CVE-2026-93834)

Summary: CVE-2026-93834 qemu-kvm: 9pfs: use-after-free race in Tlcreate/Twalk allows VM guest escape
Product: [Other] Security Response Reporter: Mauro Matteo Cascella <mcascell>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, eglynn, jdelft, jjoyce, jpretori, jschluet, jupierce, lgarciaa, lhh, mbiarnes, mburns, mgarciac, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2537961, 2537958    
Bug Blocks:    

Description Mauro Matteo Cascella 2026-09-22 16:18:01 UTC
HASH(0x55cdf58ef510)