Vulnerability · Published Oct 13, 2026 · Assigned by XEN
CVE-2026-102702Arm: multiple issues with GNTTABOP_cache_flush
High 7.5
In plain English
A high-severity security flaw 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 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] 1) XSA-437 (CVE-2023-34321) addressed issues with overflows in calculations involved in guests flushing caches through GNTTABOP_cache_flush. Unfortunately the fix there introduced a calculation which may underflow, resulting in a loop which would - at least on 64-bit Arm - take excessively long, and which would likely eventually crash the hypervisor. This is CVE-2026-102699. 2) GNTTABOP_cache_flush may be issued on memory mapped from another domain using the grant table interface. However there was no restriction to disallow the use of invalidate-without-clean against read-only grant mappings, which may corrupt the granted memory. This is CVE-2026-102702.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | xen | 4.17.7+13-g2445b30a44-0+deb12u1 | DEBIAN-CVE-2026-102702 |
| Debian:13 | xen | 4.20.4+39-gf1e1321c87-0+deb13u1 | DEBIAN-CVE-2026-102702 |
| Debian:14 | xen | 4.20.4+39-gf1e1321c87-1 | DEBIAN-CVE-2026-102702 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-102702 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-102702 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-102702 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2026-102702 |
Affected products (as reported)
Weakness: CWE-191 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H