Description
CMPXCHG8B emulation in Xen 3.3.x through 4.7.x on x86 systems allows local HVM guest OS users to obtain sensitive information from host stack memory via a "supposedly-ignored" operand size prefix.
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 | 4.8.0~rc3-1 | — |
| Debian 13 | xen | 4.8.0~rc3-1 | — |
| Debian 12 | xen | 4.8.0~rc3-1 | — |
| Debian 8 | xen | 4.4.1-9+deb8u9 | DSA-3847-1 |
| Debian 7 | xen | 4.1.6.lts1-8 | DLA-964-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | xen | 4.6.0-1ubuntu4.3 | — |
| Ubuntu 14.04 LTS | xen | 4.4.2-0ubuntu0.14.04.9 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | xen | 4.7.1_04-28.1 | SUSE-SU-2016:3208-1 |
| SLES 12 SP1 | xen | 4.5.5_04-22.6.1 | SUSE-SU-2016:3207-1 |
| SLES 12 | xen | 4.4.4_05-22.28.2 | SUSE-SU-2016:3241-1 |
| SLES 11 SP4 | xen | 4.4.4_12-46.1 | SUSE-SU-2016:3221-1 |
| SLES 11 SP3 | xen | 4.2.5_21-35.1 | SUSE-SU-2017:0718-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP2 | xen | 4.7.1_04-28.1 | SUSE-SU-2016:3208-1 |
| SLES for SAP 12 SP1 | xen | 4.5.5_04-22.6.1 | SUSE-SU-2016:3207-1 |
| SLES for SAP 12 | xen | 4.4.4_05-22.28.2 | SUSE-SU-2016:3241-1 |
| SLES for SAP 11 SP4 | xen | 4.4.4_12-46.1 | SUSE-SU-2016:3221-1 |
| SUSE OpenStack Cloud 5 | xen | 4.2.5_21-35.1 | SUSE-SU-2017:0718-1 |
| SUSE Manager Proxy 2.1 | xen | 4.2.5_21-35.1 | SUSE-SU-2017:0718-1 |
| SUSE Manager 2.1 | xen | 4.2.5_21-35.1 | SUSE-SU-2017:0718-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | xen | 4.2.5_21-35.1 | SUSE-SU-2017:0718-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xen | 4.15.1_01-1.2 | openSUSE-SU-2024:11520-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.7.1-r3 | — |
| Alpine v3.23 | xen | 4.7.1-r3 | — |
| Alpine v3.22 | xen | 4.7.1-r3 | — |
| Alpine v3.21 | xen | 4.7.1-r3 | — |
| Alpine v3.20 | xen | 4.7.1-r3 | — |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | xen | 4.7.1-r3 | — |
| Alpine v3.18 | xen | 4.7.1-r3 | — |
| Alpine v3.17 | xen | 4.7.1-r3 | — |
| Alpine v3.16 | xen | 4.7.1-r3 | — |
| Alpine v3.15 | xen | 4.7.1-r3 | — |
| Alpine v3.14 | xen | 4.7.1-r3 | — |
| Alpine v3.13 | xen | 4.7.1-r3 | — |
| Alpine v3.12 | xen | 4.7.1-r3 | — |
| Alpine v3.11 | xen | 4.7.1-r3 | — |
| Alpine v3.10 | xen | 4.7.1-r3 | — |
| Alpine v3.9 | xen | 4.7.1-r3 | — |
| Alpine v3.8 | xen | 4.7.1-r3 | — |
| Alpine v3.7 | xen | 4.7.1-r3 | — |
| Alpine v3.6 | xen | 4.7.1-r3 | — |
| Alpine v3.5 | xen | 4.7.1-r3 | — |
| Alpine v3.4 | xen | 4.6.3-r6 | — |
| Alpine v3.3 | xen | 4.6.3-r4 | — |
Advisories 8
- DLA-964-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3847-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2016:3207-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:0718-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3241-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3208-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11520-1 xen-4.15.1_01-1.2 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- SUSE-SU-2016:3221-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
References
- http://xenbits.xen.org/xsa/advisory-200.html
- GLSA-201612-56 vendor-advisory
- DSA-3847 vendor-advisory
- 1037468 vdb-entry
- 94863 vdb-entry
- https://support.citrix.com/article/CTX219378