CVE-2026-9539
libslirp TCP URG OOB Read Information Leak
- Published
- Jun 24, 2026
- Updated
- Jun 24, 2026
- Assigning CNA
- STAR_Labs
- Evidence observed
- Nov 4, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:NLow · next 30 days
- Percentile
- 12.8%
- Model date
- Nov 4, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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).
Sources
PoC for the «Snapshotting our way to CVE-2026-9539» blogpost
Responsible use
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