CVE-2026-23556: oxenstored keeps quota related use counts across domain destruction

Severity: critical (CVSS 9.4 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-09 · updated 2026-10-25
Weakness: CWE-281

Description

When oxenstored is tearing a domain down, the node data is cleaned up but the usage counts are leaked. When the domain ID is eventually reused, the new domain can create fewer nodes before beeing deemed to be over quota.

Affected products

Xen oxenstored: all versions

References

https://xenbits.xen.org/xsa/advisory-483.html
http://www.openwall.com/lists/oss-security/2026/04/28/10
http://xenbits.xen.org/xsa/advisory-483.html

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