Vulnerability in Xen
CVE-2026-62428
When grant-copy operations are processed, the respective grant may or may not already be in use by another operation (a mapping or another copy). For all copy operations the referenced guest frame is looked up. When another operation is already active for the grant (the grant is "pinned"), what is being supplied back to actually carry out permission checks and copy operation may not be consistent: The permission check may be carried out on a page different from the one involved in the copy.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
EPSS: 0.001 (1.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Xen — versions consult Xen advisory XSA-500
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-62428?
- CVE-2026-62428 is a high-severity vulnerability in Xen, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.8/10. Published 2026-07-28.
- How severe is CVE-2026-62428?
- High severity. CVSS v3 base score is 7.8 out of 10.