CVE-2026-23083

Kernel memory exhaustion via zero IP protocol

Published Feb 4, 2026 · Updated Feb 4, 2026

Memory leak in Linux Kernel allows local users to retain packet buffers by configuring a FOU receive port with IP protocol zero. The fou_udp_recv() path neither frees the skb nor resubmits it through ip_protocol_deliver_rcu() when FOU_ATTR_IPPROTO is zero. Creating that malformed FOU configuration requires local network-administration privileges; traffic to the port can accumulate unreleased kernel memory and interrupt service.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in Linux Kernel allows local users to retain packet buffers by configuring a FOU receive port with IP protocol zero. The fou_udp_recv() path neither frees the skb nor resubmits it through ip_protocol_deliver_rcu() when FOU_ATTR_IPPROTO is zero. Creating that malformed FOU configuration requires local network-administration privileges; traffic to the port can accumulate unreleased kernel memory and interrupt service.

The record

CVE
CVE-2026-23083
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 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=23461551c00628c3f3fe9cf837bf53cf8f212b63 <1cc98b8887cabb1808d2f4a37cd10a7be7574771
  2. Affected versionversion=23461551c00628c3f3fe9cf837bf53cf8f212b63 <7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5
  3. Affected versionversion=23461551c00628c3f3fe9cf837bf53cf8f212b63 <9b75dff8446ec871030d8daf5a69e74f5fe8b956
  4. Affected versionversion=23461551c00628c3f3fe9cf837bf53cf8f212b63 <b7db31a52c3862a1a32202a273a4c32e7f5f4823
  5. Affected versionversion=3.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=23461551c00628c3f3fe9cf837bf53cf8f212b63 <1cc98b8887cabb1808d2f4a37cd10a7be7574771; version=23461551c00628c3f3fe9cf837bf53cf8f212b63 <7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5; version=23461551c00628c3f3fe9cf837bf53cf8f212b63 <9b75dff8446ec871030d8daf5a69e74f5fe8b956; version=23461551c00628c3f3fe9cf837bf53cf8f212b63 <b7db31a52c3862a1a32202a273a4c32e7f5f4823; version=3.18

Published CVSS scores

7.8NIST NVDCVSS: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

T1499.002Service Exhaustion Flood

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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