CVE-2022-49840

Kernel crash via misaligned skb metadata

Published May 1, 2025 · Updated May 11, 2026

Use-after-free in Linux kernel 4.12 through 6.1-rc5 allows local users to crash the kernel through an odd-sized BPF skb test run. bpf_prog_test_run_skb() leaves skb_shared_info unaligned when an odd user-supplied packet size plus headroom is not rounded to SMP_CACHE_BYTES. Low-privileged local access to the BPF test-run path is required, and the reported fault occurs on arm64 with KFENCE enabled, producing a use-after-free read and kernel crash.

CVSS severity7.8
High
EPSS probability0.22%
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 Linux kernel 4.12 through 6.1-rc5 allows local users to crash the kernel through an odd-sized BPF skb test run. bpf_prog_test_run_skb() leaves skb_shared_info unaligned when an odd user-supplied packet size plus headroom is not rounded to SMP_CACHE_BYTES. Low-privileged local access to the BPF test-run path is required, and the reported fault occurs on arm64 with KFENCE enabled, producing a use-after-free read and kernel crash.

The record

CVE
CVE-2022-49840
Published
May 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 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=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <047824a730699c6c66df43306b80f700c9dfc2fd
  2. Affected versionversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <1b597f2d6a55e9f549989913860ad5170da04964
  3. Affected versionversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <730fb1ef974a13915bc7651364d8b3318891cd70
  4. Affected versionversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <7a704dbfd3735304e261f2787c52fbc7c3884736
  5. Affected versionversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <d3fd203f36d46aa29600a72d57a1b61af80e4a25
  6. Affected versionversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <e60f37a1d379c821c17b08f366412dce9ef3d99f
  7. Affected versionversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <eaa8edd86514afac9deb9bf9a5053e74f37edf40
  8. Affected versionversion=4.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <047824a730699c6c66df43306b80f700c9dfc2fd; version=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <1b597f2d6a55e9f549989913860ad5170da04964; version=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <730fb1ef974a13915bc7651364d8b3318891cd70; version=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <7a704dbfd3735304e261f2787c52fbc7c3884736; version=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <d3fd203f36d46aa29600a72d57a1b61af80e4a25; version=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <e60f37a1d379c821c17b08f366412dce9ef3d99f; version=1cf1cae963c2e6032aebe1637e995bc2f5d330f4 <eaa8edd86514afac9deb9bf9a5053e74f37edf40; version=4.12

Published CVSS scores

7.8CanonicalCVSS: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

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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-416Use After Free
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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