Vulnerability · Published Jul 28, 2026 · Assigned by XEN
CVE-2026-62430x86: Out-of-bounds read in vRTC emulation
High 7.5
In plain English
A high-severity race condition in Xen from Xen. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Accesses to the CMOS memory contents are done using an indirect IO port pair. Therefore Xen needs to cache the guest chosen index, and one of the usages of the index didn't take the necessary locking to avoid concurrent changes. As a result, a guest could change the index after it being checked, causing a subsequent out-of-bound read access to the contents of an array.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.21 | xen | 4.19.6-r0 | ALPINE-CVE-2026-62430 |
| Alpine:v3.22 | xen | 4.20.4-r0 | ALPINE-CVE-2026-62430 |
| Alpine:v3.23 | xen | 4.20.4-r0 | ALPINE-CVE-2026-62430 |
| Alpine:v3.24 | xen | 4.21.2-r0 | ALPINE-CVE-2026-62430 |
| Debian:12 | xen | 4.17.7-0+deb12u1 | DEBIAN-CVE-2026-62430 |
| Debian:13 | xen | 4.20.3+127-gc42374a105-0+deb13u1 | DEBIAN-CVE-2026-62430 |
| Debian:14 | xen | 4.20.3+127-gc42374a105-1 | DEBIAN-CVE-2026-62430 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-62430 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-62430 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-62430 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2026-62430 |
Affected products (as reported)
Weakness: CWE-362 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N