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CVE-2026-9539
libslirp TCP URG OOB Read Information Leak
Medium6.5EPSS 0.22%
- Published
- Updated
- Reserved
- Assigned by
- STAR_Labs
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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| STAR_LabsCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| NVDNVD · Awaiting Analysis | 3.1 | Medium6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.22% · top 87% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
Affected products
- affected < 4.9.2
References (3)
- https://gitlab.freedesktop.org/slirp/libslirp/-/work_items/93 (opens in a new tab)issue-trackingexploit
- https://gitlab.freedesktop.org/slirp/libslirp/-/commit/927bca7344e31fd58e2f7afaca784aad4400eb84 (opens in a new tab)patch
- https://gitlab.freedesktop.org/slirp/libslirp/-/releases/v4.9.2 (opens in a new tab)release-notes
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-9539)Record last updated .