Description
The Intel EPT paging code uses an optimization to defer flushing of any cached
EPT state until the p2m lock is dropped, so that multiple modifications done
under the same locked region only issue a single flush.
Freeing of paging structures however is not deferred until the flushing is
done, and can result in freed pages transiently being present in cached state.
Such stale entries can point to memory ranges not owned by the guest, thus
allowing access to unintended memory regions.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Xen | Xen | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | xen | 4.20.3+127-gc42374a105-1 | — |
| Debian 13 | xen | 4.20.3+127-gc42374a105-0+deb13u1 | — |
| Debian 12 | xen | 4.17.7-0+deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | xen | No fix yet | — |
| Ubuntu 26.04 LTS | xen | No fix yet | — |
| Ubuntu 25.10 | xen | No fix yet | — |
| Ubuntu 24.04 LTS | xen | No fix yet | — |
| Ubuntu 22.04 LTS | xen | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | xen | No fix yet | — |
| Ubuntu 18.04 LTS | xen | No fix yet | — |
| Ubuntu 16.04 LTS | xen | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | xen | 4.20.2_08-150700.3.28.1 | SUSE-SU-2026:1093-1 |
| SLES 15 SP6 | xen | 4.18.5_12-150600.3.40.1 | SUSE-SU-2026:0908-1 |
| SLES 15 SP5 | xen | 4.17.6_06-150500.3.62.2 | SUSE-SU-2026:1092-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | xen | 4.18.5_12-150600.3.40.1 | SUSE-SU-2026:0908-1 |
| SLES for SAP 15 SP5 | xen | 4.17.6_06-150500.3.62.2 | SUSE-SU-2026:1092-1 |
| SLE Micro 5.5 | xen | 4.17.6_06-150500.3.62.2 | SUSE-SU-2026:1092-1 |
| SLE HPC 15 SP5 | xen | 4.17.6_06-150500.3.62.2 | SUSE-SU-2026:1092-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xen | 4.21.1_02-1.1 | openSUSE-SU-2026:10457-1 |
| openSUSE Leap 15.6 | xen | 4.18.5_12-150600.3.40.1 | SUSE-SU-2026:0908-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.21.0-r3 | — |
| Alpine v3.23 | xen | 4.20.2-r2 | — |
| Alpine v3.22 | xen | 4.20.2-r2 | — |
| Alpine v3.21 | xen | 4.19.4-r2 | — |
| Alpine v3.20 | xen | 4.18.5-r5 | — |
Advisories 5
- WID-SEC-2026-0760 Xen und Citrix Systems XenServer: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 4, 2026
- openSUSE-SU-2026:10457-1 xen-4.21.1_02-1.1 on GA media SUSE / openSUSE Security Updates · Mar 29, 2026
- SUSE-SU-2026:1092-1 Security update for xen SUSE / openSUSE Security Updates · Mar 28, 2026
- SUSE-SU-2026:1093-1 Security update for xen SUSE / openSUSE Security Updates · Mar 28, 2026
- SUSE-SU-2026:0908-1 Security update for xen SUSE / openSUSE Security Updates · Mar 18, 2026