CVE-2026-9539

MEDIUM

libslirp TCP URG OOB Read Information Leak

Title source: cna
STIX 2.1

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).

Scores

CVSS v3 6.5
EPSS 0.0011
EPSS Percentile 1.3%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-125
Status published
Products (1)
freedesktop.org/libslirp < 4.9.2
Published Jun 24, 2026
Tracked Since Jun 24, 2026