CVE-2021-47105

Packet-processing interruption via unreleased AF_XDP buffers

Published Mar 4, 2024 · Updated May 11, 2026

Resource leak in the ice AF_XDP path of Linux kernel 5.5 through 5.15.11 allows local users to exhaust reusable UMEM buffers. The ring cleanup path in drivers/net/ethernet/intel/ice/ice_xsk.c clears each xdp_buff pointer without returning the buffer to its pool and scans beyond the entries left to clean. Reachability requires the Intel ice driver and AF_XDP socket activity; repeated cleanup removes UMEM buffers from reuse, starving other sockets and interrupting packet processing.

CVSS severity5.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource leak in the ice AF_XDP path of Linux kernel 5.5 through 5.15.11 allows local users to exhaust reusable UMEM buffers. The ring cleanup path in drivers/net/ethernet/intel/ice/ice_xsk.c clears each xdp_buff pointer without returning the buffer to its pool and scans beyond the entries left to clean. Reachability requires the Intel ice driver and AF_XDP socket activity; repeated cleanup removes UMEM buffers from reuse, starving other sockets and interrupting packet processing.

The record

CVE
CVE-2021-47105
Published
Mar 4, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 4, 2024CVE 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=2d4238f5569722197612656163d824098208519c <ad6d20da2cfbe14b7b1200d15f39e65988b0b9e8
  2. Affected versionversion=2d4238f5569722197612656163d824098208519c <afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05
  3. Affected versionversion=5.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2d4238f5569722197612656163d824098208519c <ad6d20da2cfbe14b7b1200d15f39e65988b0b9e8; version=2d4238f5569722197612656163d824098208519c <afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05; version=5.5

Published CVSS scores

5.5Canonical UbuntuCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

T1499.004Application or System Exploitation

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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