| Name | CVE-2026-93834 |
| Description | 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1149064 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| qemu (PTS) | bookworm | 1:7.2+dfsg-7+deb12u18 | vulnerable |
| bookworm (security) | 1:7.2+dfsg-7+deb12u15 | vulnerable | |
| trixie | 1:10.0.13+ds-0+deb13u1 | vulnerable | |
| trixie (security) | 1:10.0.2+ds-2+deb13u1 | vulnerable | |
| forky, sid | 1:11.1.2+ds-3 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| qemu | source | (unstable) | 1:11.1.2+ds-1 | 1149064 |
[trixie] - qemu <no-dsa> (Minor issue)
https://gitlab.com/qemu-project/qemu/-/work_items/4491
Introduced with: https://gitlab.com/qemu-project/qemu/-/commit/02cb7f3a256517cbf3136caff2863fbafc57b540 (v1.0-rc0)
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/fe9e30899ffceef25cf345ec83f76546afca19dd (master)
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/abae50de244a51ae4e959274e2ef6cbf373464ff (v11.1.2)
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/d27cd8d5a1c6ef5a506cd89cdda5c809f63e3eab (v10.0.14)