# CVE-2026-62431 — Xen

> As of 2026-07-28, CVE-2026-62431 is a HIGH-severity vulnerability in Xen, CVSS v3.1 7.5, EPSS 0.3% (27.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-62431, 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-2026-62431?

The logic to handle periodic Viridian STIMERs performs a division with an unchecked user-controlled divisor value, that can be set to zero to cause a #DE fault.

The record classifies CVE-2026-62431 under weakness class [CWE-369](https://cwe.mitre.org/data/definitions/369.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on 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:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 27.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-28

## Is CVE-2026-62431 being exploited?

It currently carries a trending score of 23 in the Threadlinqs vulnerability feed.

## Affected products and versions

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

## How to fix CVE-2026-62431

No vendor patch reference has been recorded for CVE-2026-62431 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-2026-62431

1 tracked threat in the Threadlinqs corpus references CVE-2026-62431, 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-504.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-62431
Full detection coverage and IOCs for threats exploiting CVE-2026-62431 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp