CVE-2026-62431Network attack vector

Host-wide denial of service via zero STIMER divisor

Published Jul 28, 2026 · Updated Jul 28, 2026

Divide-by-zero in Xen 4.13 and later allows guest OS users to crash the entire host through a periodic Viridian STIMER. The periodic STIMER handler divides a timer calculation by an unchecked guest-controlled divisor, so a zero value raises a #DE fault. Only unprivileged HVM guests with Viridian STIMERs enabled can trigger the crash, and Viridian extensions are disabled by default.

CVSS severity7.5
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Divide-by-zero in Xen 4.13 and later allows guest OS users to crash the entire host through a periodic Viridian STIMER. The periodic STIMER handler divides a timer calculation by an unchecked guest-controlled divisor, so a zero value raises a #DE fault. Only unprivileged HVM guests with Viridian STIMERs enabled can trigger the crash, and Viridian extensions are disabled by default.

The record

CVE
CVE-2026-62431
Published
Jul 28, 2026
Updated
Jul 28, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-369, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-369Divide By Zero
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo