CVE-2026-9539
CVE-2026-9539 · libslirp TCP URG OOB Read Information Leak
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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).
CVSS 6.5 · Medium · EPSS 0.2% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
libslirp
- Versions
- ≥ 0, < 4.9.2: Affected; ≥ 4.9.2: Not affected (semver)
Update to 4.9.2
libslirp Debian:12
- Versions
- 4.7.0-1
- 4.8.0-1
- 4.9.1-1
- 4.9.2-1
- 4.9.3-1
- 4.9.4-1
- 4.9.5-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
libslirp Debian:13
- Versions
- 4.8.0-1
- Affected ranges
- ECOSYSTEM: < 4.8.0-1+deb13u1
Update to 4.8.0-1+deb13u1
libslirp Debian:14
- Versions
- 4.8.0-1
- 4.9.1-1
- Affected ranges
- ECOSYSTEM: < 4.9.2-1
Update to 4.9.2-1
libslirp Ubuntu:20.04:LTS
- Versions
- 4.0.0-1
- 4.0.0-2
- 4.1.0-1
- 4.1.0-2
- 4.1.0-2ubuntu1
- 4.1.0-2ubuntu2
- 4.1.0-2ubuntu2.1
- 4.1.0-2ubuntu2.2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
libslirp Ubuntu:22.04:LTS
- Versions
- 4.4.0-1build1
- 4.6.1-1
- 4.6.1-1build1
- Affected ranges
- ECOSYSTEM: < 4.6.1-1ubuntu0.2
Update to 4.6.1-1ubuntu0.2
libslirp Ubuntu:24.04:LTS
- Versions
- 4.7.0-1ubuntu1
- 4.7.0-1ubuntu2
- 4.7.0-1ubuntu3
- Affected ranges
- ECOSYSTEM: < 4.7.0-1ubuntu3.1
Update to 4.7.0-1ubuntu3.1
libslirp Ubuntu:25.10
- Versions
- 4.8.0-1ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
libslirp Ubuntu:26.04:LTS
- Versions
- 4.8.0-1ubuntu1
- 4.9.1-1ubuntu1
- Affected ranges
- ECOSYSTEM: < 4.9.1-1ubuntu1.1
Update to 4.9.1-1ubuntu1.1