Description
For XSA-308 logic was introduced, as VMX VMEntry checks do not like the
exact combination of state which occurs when #DB in intercepted, Single
Stepping is active, and blocked by STI/MovSS is active, despite this being
a legitimate state to be in. The resulting VMEntry failure is fatal to
the guest.
Sadly there is another special sub-case of the above, with branch tracing
enabled. In that case the prior adjustment would still cause a VMentry
failure, as before fatal to the guest.
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 | 4.20.4+39-gf1e1321c87-1 | — |
| Debian 13 | xen | 4.20.4+39-gf1e1321c87-0+deb13u1 | — |
| Debian 12 | xen | 4.17.7+13-g2445b30a44-0+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 24.04 LTS | xen | No fix yet | — |
| Ubuntu 22.04 LTS | xen | No fix yet | — |
| Ubuntu 20.04 LTS | xen | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 | 4.20.4_06-150700.3.49.2 | SUSE-SU-2026:4942-1 |
| SLES 15 SP6 | xen | 4.18.6_03-150600.3.56.1 | SUSE-SU-2026:5140-1 |
| SLES 15 SP5 | xen | 4.17.7_02-150500.3.82.1 | SUSE-SU-2026:4641-1 |
| SLES 15 SP4 | xen | 4.16.7_16-150400.4.95.1 | SUSE-SU-2026:4642-1 |
| SLES 12 SP5 | xen | 4.12.4_76-3.154.1 | SUSE-SU-2026:4732-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | xen | 4.18.6_03-150600.3.56.1 | SUSE-SU-2026:5140-1 |
| SLES for SAP 15 SP5 | xen | 4.17.7_02-150500.3.82.1 | SUSE-SU-2026:4641-1 |
| SLES for SAP 15 SP4 | xen | 4.16.7_16-150400.4.95.1 | SUSE-SU-2026:4642-1 |
| SLE Micro 5.5 | xen | 4.17.7_02-150500.3.82.1 | SUSE-SU-2026:4641-1 |
| SLE Micro 5.4 | xen | 4.16.7_16-150400.4.95.1 | SUSE-SU-2026:4642-1 |
| SLE Micro 5.3 | xen | 4.16.7_16-150400.4.95.1 | SUSE-SU-2026:4642-1 |
| SLE HPC 15 SP5 | xen | 4.17.7_02-150500.3.82.1 | SUSE-SU-2026:4641-1 |
| SLE HPC 15 SP4 | xen | 4.16.7_16-150400.4.95.1 | SUSE-SU-2026:4642-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xen | 4.22.0_06-1.1 | openSUSE-SU-2026:12138-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.21.2-r2 | — |
| Alpine v3.23 | xen | 4.20.4-r2 | — |
| Alpine v3.22 | xen | 4.20.4-r2 | — |
| Alpine v3.21 | xen | 4.19.6-r2 | — |
Advisories 7
- SUSE-SU-2026:5140-1 Security update for xen SUSE / openSUSE Security Updates · Nov 10, 2026
- WID-SEC-2026-3930 Xen: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
- SUSE-SU-2026:4942-1 Security update for xen SUSE / openSUSE Security Updates · Oct 31, 2026
- SUSE-SU-2026:4732-1 Security update for xen SUSE / openSUSE Security Updates · Oct 20, 2026
- openSUSE-SU-2026:12138-1 xen-4.22.0_06-1.1 on GA media SUSE / openSUSE Security Updates · Oct 15, 2026
- SUSE-SU-2026:4641-1 Security update for xen SUSE / openSUSE Security Updates · Oct 14, 2026
- SUSE-SU-2026:4642-1 Security update for xen SUSE / openSUSE Security Updates · Oct 14, 2026