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CVE-2016-9818 Xen CVE debrief

CVE-2016-9818 is a Xen vulnerability affecting ARM deployments in which a local guest OS user can trigger a denial of service by causing an asynchronous abort while the hypervisor is at HYP. The practical impact is a host crash, so this is primarily an availability issue for organizations running affected Xen versions on ARM systems. Vendor guidance and a patch were published alongside the vulnerability disclosure.

Vendor
Xen
Product
Unknown
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-27
Original CVE updated
2026-05-13
Advisory published
2017-02-27
Advisory updated
2026-05-13

Who should care

System and virtualization administrators running Xen on ARM, especially those hosting untrusted or locally interactive guest workloads, should prioritize this issue because a guest-side action can crash the host.

Technical summary

NVD describes CVE-2016-9818 as a local-attack issue in Xen through 4.7.x on ARM where a guest OS user can cause a host crash via an asynchronous abort while the hypervisor is at HYP. The official record maps the issue to CVSS 3.0 AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H and CWE-284.

Defensive priority

Medium. The attack requires local guest-level access, but successful exploitation can take down the host and disrupt all workloads on it.

Recommended defensive actions

  • Apply the Xen vendor advisory and patch referenced by XSA-201.
  • Upgrade affected Xen deployments to a non-vulnerable release according to vendor guidance.
  • Review ARM hypervisor hosts that run untrusted guest workloads and prioritize patching those systems first.
  • Validate package-level vendor advisories for your Linux distribution or platform, since downstream fixes may be delivered separately.
  • Increase availability monitoring and incident response readiness for Xen hosts that cannot be patched immediately.

Evidence notes

The CVE record was published on 2017-02-27 and last modified on 2026-05-13. The supplied NVD record states that the issue affects Xen through 4.7.x on ARM and can let a local guest OS user cause a host crash via an asynchronous abort while at HYP. The reference set includes Xen advisory XSA-201, the associated patch, OSS-Security mailing list posts from 2016-11-29 and 2016-12-05, SecurityFocus BID 94581, SecurityTracker 1037358, and Gentoo GLSA-201612-56, supporting the vendor and third-party reporting timeline.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-9818 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-9818

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-9818 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-9818

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.