Buffer overflow in Xen - CVE-2026-79605
Published: September 8, 2026
Vulnerability identifier: #VU147394
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-79605
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to missing upper bounds checking in blkif->last_sect handling when processing guest-supplied blkif last-sector values. A remote user can provide a value larger than 7 to access memory beyond the mapped grant and execute arbitrary code.
The affected tapdisk process normally runs as root in dom0.
Affected software
Xen
How to mitigate CVE-2026-79605
Install security update from vendor's website.