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TI-2025-35969 Aliases CVE-2025-58151GHSA-78gx-8v3c-jqwc

varstored: TOCTOU issues with mapped guest memory

Priority MEDIUM 41CWE-367Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

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

Summary

varstored is a component of the Xapi toolstack handling UEFI Variables for a VM. It has a communication path with OVMF inside the VM involving mapping a buffer prepared by OVMF. Within varstored, there were insufficient compiler barriers, creating TOCTOU issues with data in the shared buffer. The exact vulnerable behaviour depends on the code generated by the compiler. In a build of varstored using default settings, the attacker can control an index used in a jump table.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00137 3rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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
Xenvarstoredall—No fix listedCNA
  • varstored VendorXen Affected all Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-58151
  2. 2026-10-03 Alias added: GHSA-78gx-8v3c-jqwc

References

Other 1

  • TI-2012-00210 The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix… CVSS 2.0HIGH 7.2
  • TI-2023-07042 Information disclosure through error messages in AMD Ryzen™ 3000 Series Desktop… CVSS 3.1MEDIUM 5.5
  • TI-2015-04333 The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used… CVSS 2.0HIGH 9.3
  • TI-2015-06741 The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows… CVSS 3.1CRITICAL 10.0
  • TI-2018-06436 A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures… CVSS 3.0HIGH 7.8
  • TI-2024-20522 x86: Incorrect logic for BTC/SRSO mitigations CVSS 3.1HIGH 7.5
See all 541 →

Sources

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