Description
Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES
command within a transaction due to an assert() triggering.
In case xenstored was built with NDEBUG #defined nothing bad will
happen, as assert() is doing nothing in this case. Note that the
default is not to define NDEBUG for xenstored builds even in release
builds of Xen.
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 | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xen | 4.21.1_04-1.1 | openSUSE-SU-2026:10660-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.21.1-r3 | — |
| Alpine v3.23 | xen | 4.20.3-r2 | — |
| Alpine v3.22 | xen | 4.20.3-r2 | — |
| Alpine v3.21 | xen | 4.19.5-r2 | — |
| Alpine v3.20 | xen | 4.18.5-r7 | — |
Advisories 2
- WID-SEC-2026-1306 Xen und Citrix Systems XenServer: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 4, 2026
- openSUSE-SU-2026:10660-1 xen-4.21.1_04-1.1 on GA media SUSE / openSUSE Security Updates · Apr 30, 2026