# CVE-2023-6693: Qemu: virtio-net: stack buffer overflow in virtio_net_flush_tx()

Status: published. Published: 2024-01-02. Updated: 2026-11-05.

A stack based buffer overflow was found in the virtio-net device of QEMU. This issue occurs when flushing TX in the virtio_net_flush_tx function if guest features VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1 and VIRTIO_NET_F_MRG_RXBUF are enabled. This could allow a malicious user to overwrite local variables allocated on the stack. Specifically, the `out_sg` variable could be used to read a part of process memory and send it to the wire, causing an information leak.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 8 (virt-devel:rhel): ≥ 8100020240314161907.e155f54d; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (virt:rhel): ≥ 8100020240314161907.e155f54d; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (qemu-kvm): ≥ 17:9.0.0-10.el9_5.3; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (qemu-kvm): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (qemu-kvm): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (qemu-kvm-ma): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 Advanced Virtualization (virt:av/qemu-kvm): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 4.9 (medium); CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.33% as of 2026-11-04; percentile 26.26%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-121

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2024:2962 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2025:4492 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2023-6693 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2254580 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2024:2962 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/security/cve/CVE-2023-6693 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred)

- https://bugzilla.redhat.com/show_bug.cgi?id=2254580 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred)

- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OYGUN5HVOXESW7MSNM44E4AE2VNXQB6Y/ (ADP: CVE; x_transferred)

- https://security.netapp.com/advisory/ntap-20240208-0004/ (ADP: CVE; x_transferred)

- https://lists.debian.org/debian-lts-announce/2025/04/msg00042.html (ADP: CVE)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-6693; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-6693; retrieved 2026-11-05; source updated Not reported

Revision: 0ded75ee8e444b8b05a41f9e7e52becf1bad33824b561fd4dd74c0f3636d4380

Canonical: https://y2.dev/cve/CVE-2023-6693

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