CVE-2026-9539
6.5
MEDIUM
CVSS 3.1
EPSS 0.11%
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).
How to fix CVE-2026-9539
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- —no fix listed
Is CVE-2026-9539 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |