CVE-2025-21687

Local privilege escalation via unchecked VFIO offsets

Published Feb 10, 2025 · Updated Aug 5, 2026

Out-of-bounds access in Linux kernel VFIO platform handling allows local users to read or write kernel memory through device syscalls. vfio_platform_read and vfio_platform_write accept a user-controlled count and 40-bit file offset without checking the selected region's size, so MMIO proceeds beyond the mapped device window. Reachability requires an open VFIO platform device descriptor; the resulting access can disclose kernel memory, corrupt kernel or device state, or crash or hang the system.

CVSS severity7.8
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 Linux kernel VFIO platform handling allows local users to read or write kernel memory through device syscalls. vfio_platform_read and vfio_platform_write accept a user-controlled count and 40-bit file offset without checking the selected region's size, so MMIO proceeds beyond the mapped device window. Reachability requires an open VFIO platform device descriptor; the resulting access can disclose kernel memory, corrupt kernel or device state, or crash or hang the system.

The record

CVE
CVE-2025-21687
Published
Feb 10, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=4.1
  2. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <1485932496a1b025235af8aa1e21988d6b7ccd54
  3. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <665cfd1083866f87301bbd232cb8ba48dcf4acce
  4. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <6bcb8a5b70b80143db9bf12dfa7d53636f824d53
  5. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <92340e6c5122d823ad064984ef7513eba9204048
  6. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <9377cdc118cf327248f1a9dde7b87de067681dc9
  7. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <a20fcaa230f7472456d12cf761ed13938e320ac3
  8. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <c981c32c38af80737a2fedc16e270546d139ccdd
  9. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <ce9ff21ea89d191e477a02ad7eabf4f996b80a69
  10. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <d19a8650fd3d7aed8d1af1d9a77f979a8430eba1
  11. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <ed81d82bb6e9df3a137f2c343ed689e6c68268ef
  12. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <f21636f24b6786c8b13f1af4319fa75ffcf17f38
  13. Affected versionversion=6e3f264560099869f68830cb14b3b3e71e5ac76a <f65ce06387f8c1fb54bd59e18a8428248ec68eaf

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.1; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <1485932496a1b025235af8aa1e21988d6b7ccd54; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <665cfd1083866f87301bbd232cb8ba48dcf4acce; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <6bcb8a5b70b80143db9bf12dfa7d53636f824d53; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <92340e6c5122d823ad064984ef7513eba9204048; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <9377cdc118cf327248f1a9dde7b87de067681dc9; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <a20fcaa230f7472456d12cf761ed13938e320ac3; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <c981c32c38af80737a2fedc16e270546d139ccdd; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <ce9ff21ea89d191e477a02ad7eabf4f996b80a69; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <d19a8650fd3d7aed8d1af1d9a77f979a8430eba1; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <ed81d82bb6e9df3a137f2c343ed689e6c68268ef; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <f21636f24b6786c8b13f1af4319fa75ffcf17f38; version=6e3f264560099869f68830cb14b3b3e71e5ac76a <f65ce06387f8c1fb54bd59e18a8428248ec68eaf

Published CVSS scores

7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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

T1068Exploitation for Privilege Escalation

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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