CVE-2026-9539
Publication date 24 June 2026
Last updated 26 June 2026
Ubuntu priority
Description
An out-of-bounds heap read and integer underflow in the TCP urgent data handling (sosendoob) in freedesktop.org libslirp version before v4.9.2 on hypervisor host environments (e.g., QEMU) allows a privileged guest VM attacker (root or CAP_NET_RAW) to leak gigabytes of sensitive host-process heap memory via sending crafted TCP segments with manipulated URG flags and urgent pointers (ti_urp).
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| libslirp | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
6.5 · Medium
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-9539
- https://gitlab.freedesktop.org/slirp/libslirp/-/work_items/93
- https://gitlab.freedesktop.org/slirp/libslirp/-/commit/927bca7344e31fd58e2f7afaca784aad4400eb84 (v4.9.2)
- https://gitlab.freedesktop.org/slirp/libslirp/-/commit/927bca7344e31fd58e2f7afaca784aad4400eb84
- https://gitlab.freedesktop.org/slirp/libslirp/-/releases/v4.9.2