CVE-2026-64289

System hang via unbounded cache-invalidation parameters

Published Jul 25, 2026 · Updated Jul 25, 2026

Denial of service in the Linux Kernel iommufd component allows local users to make the system unresponsive via a cache-invalidation ioctl. iommufd_hwpt_invalidate() accepts entry_len and entry_num values bounded only by U32_MAX, causing an uninterrupted zero-byte scan or an unrescheduled backend loop. Access to an iommufd hardware page-table object is required; either oversized field can monopolize a CPU and trigger the soft-lockup watchdog.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux Kernel iommufd component allows local users to make the system unresponsive via a cache-invalidation ioctl. iommufd_hwpt_invalidate() accepts entry_len and entry_num values bounded only by U32_MAX, causing an uninterrupted zero-byte scan or an unrescheduled backend loop. Access to an iommufd hardware page-table object is required; either oversized field can monopolize a CPU and trigger the soft-lockup watchdog.

The record

CVE
CVE-2026-64289
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-606, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.8
  2. Affected versionversion=8c6eabae3807e048b9f17733af5e20500fbf858c <2c6381d90898089287e0a358f06f89f6b4b389f2
  3. Affected versionversion=8c6eabae3807e048b9f17733af5e20500fbf858c <32ca4aed2a66205b072fcfecabe220289a8149ff
  4. Affected versionversion=8c6eabae3807e048b9f17733af5e20500fbf858c <4d70986002f2f3eaaed89124fb2522bded38b016
  5. Affected versionversion=8c6eabae3807e048b9f17733af5e20500fbf858c <d2bd041e0efaf7d81789779b135279d18b33d6d5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.8; version=8c6eabae3807e048b9f17733af5e20500fbf858c <2c6381d90898089287e0a358f06f89f6b4b389f2; version=8c6eabae3807e048b9f17733af5e20500fbf858c <32ca4aed2a66205b072fcfecabe220289a8149ff; version=8c6eabae3807e048b9f17733af5e20500fbf858c <4d70986002f2f3eaaed89124fb2522bded38b016; version=8c6eabae3807e048b9f17733af5e20500fbf858c <d2bd041e0efaf7d81789779b135279d18b33d6d5

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/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.

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No observations available

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

Weakness, pattern, technique

CWE-606Unchecked Input for Loop Condition
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

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Your stack

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