CVE-2025-39806

Kernel memory corruption via short HID descriptor

Published Sep 16, 2025 · Updated Sep 16, 2025

Out-of-bounds access in the Linux kernel allows physically proximate attackers to corrupt kernel memory through a malicious HID device. mt_report_fixup reads descriptor byte 607 and conditionally writes 0x25 there without first verifying that the descriptor is at least 608 bytes long. USB or Bluetooth HID enumeration must reach the driver; the access can disclose adjacent heap data, corrupt a neighboring object, or crash the kernel.

CVSS severity8.8
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds access in the Linux kernel allows physically proximate attackers to corrupt kernel memory through a malicious HID device. mt_report_fixup reads descriptor byte 607 and conditionally writes 0x25 there without first verifying that the descriptor is at least 608 bytes long. USB or Bluetooth HID enumeration must reach the driver; the access can disclose adjacent heap data, corrupt a neighboring object, or crash the kernel.

The record

CVE
CVE-2025-39806
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1200
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record 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=1d5c7d0a49ec9d8786f266ac6d1d7c4960e1787b <d4e6e2680807671e1c73cd6a986b33659ce92f2b
  2. Affected versionversion=45ec9f17ce46417fc4eccecf388c99e81fb7fcc1 <7ab7311c43ae19c66c53ccd8c5052a9072a4e338
  3. Affected versionversion=6.11
  4. Affected versionversion=7d91a0b2151a9c3b61d44c85c8eba930eddd1dd0 <4263e5851779f7d8ebfbc9cc7d2e9b0217adba8d
  5. Affected versionversion=c8000deb68365b461b324d68c7ea89d730f0bb85 <0379eb8691b9c4477da0277ae0832036ca4410b4
  6. Affected versionversion=c8000deb68365b461b324d68c7ea89d730f0bb85 <3055309821dd3da92888f88bad10f0324c3c89fe
  7. Affected versionversion=c8000deb68365b461b324d68c7ea89d730f0bb85 <c13e95587583d018cfbcc277df7e02d41902ac5a
  8. Affected versionversion=d189e24a42b8bd0ece3d28801d751bf66dba8e92

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1d5c7d0a49ec9d8786f266ac6d1d7c4960e1787b <d4e6e2680807671e1c73cd6a986b33659ce92f2b; version=45ec9f17ce46417fc4eccecf388c99e81fb7fcc1 <7ab7311c43ae19c66c53ccd8c5052a9072a4e338; version=6.11; version=7d91a0b2151a9c3b61d44c85c8eba930eddd1dd0 <4263e5851779f7d8ebfbc9cc7d2e9b0217adba8d; version=c8000deb68365b461b324d68c7ea89d730f0bb85 <0379eb8691b9c4477da0277ae0832036ca4410b4; version=c8000deb68365b461b324d68c7ea89d730f0bb85 <3055309821dd3da92888f88bad10f0324c3c89fe; version=c8000deb68365b461b324d68c7ea89d730f0bb85 <c13e95587583d018cfbcc277df7e02d41902ac5a; version=d189e24a42b8bd0ece3d28801d751bf66dba8e92

Published CVSS scores

7.0UbuntuCVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8LinuxCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.1UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1200Hardware Additions

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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