# CVE-2026-48914: QEMU heap overflow in virtio-blk SCSI request handling

Source: https://junglewise.ai/threats/cve-2026-48914-qemu-heap-overflow-in-virtio-blk-scsi-request-handling  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-12. Updated: 2026-06-12  
License: CC BY 4.0 with a link back

CVE-2026-48914 · Severity: medium · CVSS 6.7 · Published 2026-06-12

A security vulnerability was found in QEMU, a widely used virtualization software that allows computers to run multiple operating systems simultaneously. A user with high privileges within a virtual machine could exploit a flaw in the virtual disk component to crash the host system or potentially interfere with other operations. This could lead to a denial of service, impacting the availability of the virtualized environment and the host server.

Technologies: [Qemu](https://junglewise.ai/threats/technologies/qemu). Vendors: [Qemu](https://junglewise.ai/threats/vendors/qemu).

## Quick answers

**Is CVE-2026-48914 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48914 being exploited in the wild.

**How severe is CVE-2026-48914?** Medium severity, with a CVSS score of 6.7, published 12 June 2026.

**Which products and versions are affected?** Qemu unspecified.

**Is there a fix for CVE-2026-48914?** A patch was published on 2026-05-26: Upstream patch submitted to qemu-devel Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-48914 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-48914?** Check whether you run Qemu at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A heap-based buffer overflow exists in QEMU's virtio-blk device during the handling of VIRTIO_BLK_T_SCSI_CMD requests. The vulnerability is caused by a failure to validate the size of input descriptors before writing the 4-byte virtio_scsi_inhdr.errors field. An attacker with high privileges in a guest VM can provide a descriptor pointing to an MMIO address with a length of only 1 byte, forcing QEMU to allocate a 1-byte heap bounce buffer. When QEMU writes the 4-byte error status, it performs an out-of-bounds write into the host's heap memory. This can result in a crash of the QEMU process (Denial of Service). A patch has been proposed to add the missing size check in hw/block/virtio-blk.c.

## Affected products

- QEMU QEMU unspecified

## Timeline

- 2026-05-26: patched: Upstream patch submitted to qemu-devel
- 2026-06-12: disclosed: CVE published and Red Hat advisory released

## References

- [https://access.redhat.com/security/cve/CVE-2026-48914](https://access.redhat.com/security/cve/CVE-2026-48914)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2488283](https://bugzilla.redhat.com/show_bug.cgi?id=2488283)
- [https://lore.kernel.org/qemu-devel/20260526154957.1741622-1-stefanha@redhat.com/](https://lore.kernel.org/qemu-devel/20260526154957.1741622-1-stefanha@redhat.com/)

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