CVE-2026-9539
Medium
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).
SeverityMedium
CVSS6.5
Exploit probability—
ProductFreedesktop.org Libslirp
PublishedJun 24, 2026
First seenJun 24, 2026
Weakness typeCWE-125Out-of-bounds read
How to fix
Update
- freedesktop.org libslirp4.9.2 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| freedesktop.org libslirp | v < 4.9.2 | 4.9.2 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.