CVE-2024-26864

Local privilege escalation via socket refcount underflow

Published Apr 17, 2024 · Updated Aug 5, 2026

Affected Linux kernel releases allow local users to execute code in the kernel through a TCP/DCCP socket reference-count underflow. __inet_hash_connect() reverses an ehash insertion with sk_nulls_add_node_rcu(), which takes a reference that check_established() never acquired, so the later sock_put() underflows the socket reference count. An unprivileged local process can drive the path through connect(), and exploitation can expose or modify kernel memory, hijack control flow, panic the host, or exhaust memory.

CVSS severity7.8
High
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Affected Linux kernel releases allow local users to execute code in the kernel through a TCP/DCCP socket reference-count underflow. __inet_hash_connect() reverses an ehash insertion with sk_nulls_add_node_rcu(), which takes a reference that check_established() never acquired, so the later sock_put() underflows the socket reference count. An unprivileged local process can drive the path through connect(), and exploitation can expose or modify kernel memory, hijack control flow, panic the host, or exhaust memory.

The record

CVE
CVE-2024-26864
Published
Apr 17, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-200, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 17, 2024CVE 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=334a8348b2df26526f3298848ad6864285592caf <856baaa100cd288d3685eedae9a129c996e7e755
  2. Affected versionversion=6.1.80 <6.1.83
  3. Affected versionversion=6.6.19 <6.6.23
  4. Affected versionversion=66b60b0c8c4a163b022a9f0ad6769b0fd3dc662f <04d9d1fc428ac9f581d55118d67e0cb546701feb
  5. Affected versionversion=66b60b0c8c4a163b022a9f0ad6769b0fd3dc662f <ad105cde6b261b8b05ec872fe7d1987417d7fe5a
  6. Affected versionversion=6.7.7 <6.7.11
  7. Affected versionversion=6.8
  8. Affected versionversion=729bc77af438a6e67914c97f6f3d3af8f72c0131 <86d9b040421bbd26425f5a3edc226f57ecdecbfe
  9. Affected versionversion=f8c4a6b850882bc47aaa864b720c7a2ee3102f39 <1b20e61d36f490319d3fbdedd410155232ab5190

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=334a8348b2df26526f3298848ad6864285592caf <856baaa100cd288d3685eedae9a129c996e7e755; version=6.1.80 <6.1.83; version=6.6.19 <6.6.23; version=66b60b0c8c4a163b022a9f0ad6769b0fd3dc662f <04d9d1fc428ac9f581d55118d67e0cb546701feb; version=66b60b0c8c4a163b022a9f0ad6769b0fd3dc662f <ad105cde6b261b8b05ec872fe7d1987417d7fe5a; version=6.7.7 <6.7.11; version=6.8; version=729bc77af438a6e67914c97f6f3d3af8f72c0131 <86d9b040421bbd26425f5a3edc226f57ecdecbfe; version=f8c4a6b850882bc47aaa864b720c7a2ee3102f39 <1b20e61d36f490319d3fbdedd410155232ab5190
The Linux Kernel Organization · Linux Kernelversion=6.8; version=729bc77af438 <86d9b040421b

Published CVSS scores

5.9CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.3SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
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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