CVE-2025-21883

Kernel crash via stale VF mailbox entries

Published Mar 27, 2025 · Updated May 11, 2026

Use-after-free in the ICE driver in affected Linux kernels allows local users to crash the kernel while configuring SR-IOV virtual functions. When ice_ena_vfs fails after creating VF entries, its error path frees the VFs but leaves them linked in the PF-VF mailbox snapshot list. The trigger requires local access, an ICE device, switchdev mode, and SR-IOV configuration; reusing the stale entries causes list corruption, a kernel BUG, or a KASAN report.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the ICE driver in affected Linux kernels allows local users to crash the kernel while configuring SR-IOV virtual functions. When ice_ena_vfs fails after creating VF entries, its error path frees the VFs but leaves them linked in the PF-VF mailbox snapshot list. The trigger requires local access, an ICE device, switchdev mode, and SR-IOV configuration; reusing the stale entries causes list corruption, a kernel BUG, or a KASAN report.

The record

CVE
CVE-2025-21883
Published
Mar 27, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=6.4
  2. Affected versionversion=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <34393fd78d7183a007eaf0090966ebedcc29bd57
  3. Affected versionversion=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <3c01102bec9592928e6b155da41cfcd5d25a2066
  4. Affected versionversion=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <79990cf5e7aded76d0c092c9f5ed31eb1c75e02c
  5. Affected versionversion=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <a4880583f88deba63504ce1c8287a70d39c01378

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.4; version=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <34393fd78d7183a007eaf0090966ebedcc29bd57; version=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <3c01102bec9592928e6b155da41cfcd5d25a2066; version=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <79990cf5e7aded76d0c092c9f5ed31eb1c75e02c; version=8cd8a6b17d275a45e3722d0215f6115b687c8c3e <a4880583f88deba63504ce1c8287a70d39c01378

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Amazon LinuxCVSS: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

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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