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TI-2026-73416 Aliases CVE-2026-110111GHSA-9p53-2254-x397

Prototype pollution in Xen Orchestra enables privilege escalation

Priority LOW 37CWE-1321Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Xen Orchestra before 6.9.0 contains an improper access control flaw in the vm.importFromEsxi and vm.importMultipleFromEsxi methods that any authenticated user can reach. An attacker can point xo-server at a malicious ESXi host serving a crafted .vmx file that pollutes Object.prototype (CWE-1321), so permission-less accounts inherit global administrator rights. The flaw also enables remote code execution.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Xen Orchestra before 6.9.0 contains an improper access control vulnerability that allows any authenticated user to become global administrator by abusing the unprotected vm.importFromEsxi and vm.importMultipleFromEsxi methods. Attackers can point xo-server at a malicious ESXi host serving a crafted .vmx file with __proto__.permission set, polluting Object.prototype so permission-less accounts inherit admin rights and enabling remote code execution.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00617 49th percentileScored 2026-11-07
Fix Fixed xen-orchestra (vatesfr): 6.9.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
vatesfrxen-orchestrabefore 6.9.06.9.0Patch availableCNA
  • xen-orchestra Vendorvatesfr Affected before 6.9.0 Fixed in 6.9.0 Patch available CNA

Remediation

Upgrade Xen Orchestra to version 6.9.0 or later, which is the fixed version.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA xen-orchestra (vatesfr) Fixed in 6.9.0

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-110111
  2. 2026-10-13 Alias added: GHSA-9p53-2254-x397
  3. 2026-10-14 Priority changed: MEDIUM → LOW
  4. 2026-10-26 CISA SSVC decision points changed

References

Advisory 1

  • TI-2026-76939 Authorization bypass in Xen Orchestra user.set API lets users alter others CVSS 4.0MEDIUM 5.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences