CVE-2026-74580
Linux kernel vhost stale IOTLB cache "Vghost" privilege escalation
CVE-2026-74580 ("Vghost") is a Linux kernel vhost flaw. A stale vring metadata cache lets memory access escape the mapped region. The kernel CNA scores it CVSS 3.1 8.8 (High). A local user with vhost device access can gain root. A guest can attack the host QEMU process in a narrow vIOMMU setup. Fixed upstream in 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45, 7.1.9 and 7.2. Researcher PoC public. Not in CISA KEV.
- CVSS
- 8.8
- Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Class
- LPE
- Status
- PoC Available
- KEV
- Not in CISA KEV
- 0-day
- No
- Vendor
- Linux
- Products
- Linux kernel (vhost)
- Affected
- Linux kernel from 4.11 up to the fixed stable releases: before 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45 and 7.1.9, and mainline before 7.2. Vendor kernels may carry a backport under an older base version.
- Fixed
- Upstream stable 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45, 7.1.9 and 7.2 (mainline fix de845981da67). Debian DSA-6466-1 and DLA-4777-1, Ubuntu kernel updates, Amazon Linux, Oracle Linux ELSA-2026-500248, and Red Hat for RHEL 7 ELS and 9.6 EUS.
- CWE
- CWE-825
- Published
- 21 Aug 2026
- Updated
- 14 Oct 2026
The status above is the claim. Links do not upgrade it.
CVE-2026-74580 is a flaw in the Linux kernel vhost subsystem. Vhost speeds up virtio devices such as vhost-net and vhost-vsock for KVM guests. The kernel kept a cached ring mapping after the ring was reconfigured. Later accesses could then reach memory outside the mapped region.
The Linux kernel CNA published the CVE on 21 August 2026. The kernel CNA scores it CVSS 3.1 8.8 (High). NVD shows that CNA score and has not added its own. Red Hat rates it Important with its own CVSS 3.1 score of 7.3. SUSE rates it moderate with a SUSE score of 5.5. Ubuntu gives it Medium priority.
The flaw dates back to Linux 4.11. Fixed upstream stable releases are 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45, 7.1.9 and 7.2. Debian, Ubuntu, Amazon Linux and Oracle Linux list fixed kernels. Red Hat has fixes for RHEL 7 ELS and RHEL 9.6 EUS. Red Hat still lists RHEL 8, 9 and 10 kernels as affected. SUSE lists the issue as pending.
Fourie Zhang of the TencentOS Security Team (Tencent Zhuque Lab) disclosed the issue as "Vghost" on 14 October 2026. Corvus AI is credited with assisting the research.
The researchers describe two paths. A local user who can open a vhost device node can gain root. A malicious guest can corrupt the host QEMU process when the VM uses a virtual IOMMU and the virtio device has iommu_platform enabled.
The CVE is not in the CISA KEV catalog. No in-the-wild exploitation is reported. The researchers published a PoC in a GitHub repository. ThreatWire has not run or verified it. The PoC link field points to it; the URL is not repeated here.