CVE-2026-62428: grant-table: type confusion in grant-copy

Vulnerability summary

CVE-2026-62428 is a high (CVSS 7.8) vulnerability in xen. EPSS estimates a 0.11% chance of exploitation in the next 30 days, higher than 1.5% of scored vulnerabilities.

Timeline

1. 28-07-2026
   PublishedVulnerability first disclosed.
2. 28-07-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.