What is CVE-2026-9539?

CVE-2026-9539 is a medium-severity vulnerability in Freedesktop.org Libslirp, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-06-24.

How severe is CVE-2026-9539?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Out-of-bounds Read in Freedesktop.org Libslirp

CVE-2026-9539

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_…

Vulnerability class: Buffer Overflow

EPSS: 0.001 (1.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 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.

Affected products

Freedesktop.org Libslirp — versions 0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

info@starlabs.sg (issue-tracking)
info@starlabs.sg (patch)
info@starlabs.sg (release-notes)

Frequently asked questions

What is CVE-2026-9539?: CVE-2026-9539 is a medium-severity vulnerability in Freedesktop.org Libslirp, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-06-24.
How severe is CVE-2026-9539?: Medium severity. CVSS v3 base score is 6.5 out of 10.