Description
QEMU, as used in Xen 3.3.x through 4.5.x, does not properly restrict access to PCI command registers, which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device, which triggers an Unsupported Request (UR) response.
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 | qemu | 1:2.3+dfsg-3 | — |
| Debian 14 | xen | 4.2.0~rc2-1 | — |
| Debian 13 | qemu | 1:2.3+dfsg-3 | — |
| Debian 13 | xen | 4.2.0~rc2-1 | — |
| Debian 12 | qemu | 1:2.3+dfsg-3 | — |
| Debian 12 | xen | 4.2.0~rc2-1 | — |
| Debian 8 | qemu | 1:2.1+dfsg-12 | DSA-3259-1 |
| Debian 7 | xen | 4.1.6.1-1+deb7u1 | DLA-479-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | qemu | 2.0.0+dfsg-2ubuntu1.11 | USN-2608-1 |
| Ubuntu 14.04 LTS | xen | 4.4.1-0ubuntu0.14.04.5 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | xen | 4.4.2_02-15.1 | SUSE-SU-2015:0701-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 | xen | 4.4.2_02-15.1 | SUSE-SU-2015:0701-1 |
Advisories 4
- DLA-479-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3259-1 qemu - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2608-1 qemu, qemu-kvm vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2015:0701-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
References
- 72577 vdb-entry
- GLSA-201504-04 vendor-advisory
- https://support.citrix.com/article/CTX206006
- DSA-3259 vendor-advisory
- FEDORA-2015-5295 vendor-advisory
- FEDORA-2015-5208 vendor-advisory
- http://support.citrix.com/article/CTX201145
- [Qemu-devel] 20150331 [PATCH][XSA-126] xen: limit guest control of PCI command register mailing-list
- http://xenbits.xen.org/xsa/advisory-126.html
- openSUSE-SU-2015:0732 vendor-advisory
- USN-2608-1 vendor-advisory
- 1031998 vdb-entry
- FEDORA-2015-5402 vendor-advisory