# CVE-2026-62428 — Xen

> As of 2026-07-28, CVE-2026-62428 is a HIGH-severity vulnerability in Xen, CVSS v3.1 7.8, EPSS 0.1% (1.4th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-62428, most recently “Multiple Vulnerabilities in Citrix XenServer 8.4 and 9 Enable Guest-to-Host Escalation and Denial of Service (CVE-2026-42492, CVE-2026-62428, CVE-2026-62431, CVE-2026-62432, CVE-2026-62434, CVE-2026-62435, CVE-2026-62436)”.

**Last updated:** 2026-07-28

## What is CVE-2026-62428?

When grant-copy operations are processed, the respective grant may or may not already be in use by another operation (a mapping or another copy). For all copy operations the referenced guest frame is looked up. When another operation is already active for the grant (the grant is "pinned"), what is being supplied back to actually carry out permission checks and copy operation may not be consistent: The permission check may be carried out on a page different from the one involved in the copy.

The record classifies CVE-2026-62428 under weakness class [CWE-367](https://intel.threadlinqs.com/cwe/CWE-367). Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 84 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 1.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-28

## Is CVE-2026-62428 being exploited?

It currently carries a trending score of 17 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Xen](https://intel.threadlinqs.com/vendors/xen): Xen

## How to fix CVE-2026-62428

No vendor patch reference has been recorded for CVE-2026-62428 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-62428

1 tracked threat in the Threadlinqs corpus references CVE-2026-62428, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Vulnerabilities in Citrix XenServer 8.4 and 9 Enable Guest-to-Host Escalation and Denial of Service (CVE-2026-42492, CVE-2026-62428, CVE-2026-62431, CVE-2026-62432, CVE-2026-62434, CVE-2026-62435, CVE-2026-62436)](https://intel.threadlinqs.com/threat/TL-2026-1781) — HIGH · 2026-07-31

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [xenbits.xenproject.org](https://xenbits.xenproject.org/xsa/advisory-500.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-62428
Full detection coverage and IOCs for threats exploiting CVE-2026-62428 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp