CVE-2023-54243

Kernel memory corruption via freed ebtables table blob

Published Dec 30, 2025 · Updated Dec 30, 2025

Use-after-free in Linux kernel ebtables allows local users to read or write kernel memory and crash affected systems through setsockopt. In do_replace, find_table_lock can return a valid table with a nonzero status; the code stores the replacement blob in table->private before the caller frees that still-referenced blob. Reachability requires CAP_NET_ADMIN over a user namespace, which an unprivileged local user can obtain in a fresh user and network namespace; later dereferences can hijack control flow or panic the kernel.

CVSS severity7.8
High
EPSS probability0.14%
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 ebtables allows local users to read or write kernel memory and crash affected systems through setsockopt. In do_replace, find_table_lock can return a valid table with a nonzero status; the code stores the replacement blob in table->private before the caller frees that still-referenced blob. Reachability requires CAP_NET_ADMIN over a user namespace, which an unprivileged local user can obtain in a fresh user and network namespace; later dereferences can hijack control flow or panic the kernel.

The record

CVE
CVE-2023-54243
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 2025Record 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=3.15
  2. Affected versionversion=8b5740915a9faa8b1fa9166193a33e2a9ae30ec6
  3. Affected versionversion=8ed40c122919cd79bc3c059e5864e5e7d9d455f0
  4. Affected versionversion=a3bc0f8ea439762aa62d40a295157410498cbea7
  5. Affected versionversion=c58dd2dd443c26d856a168db108a0cd11c285bf3 <3dd6ac973351308d4117eda32298a9f1d68764fd
  6. Affected versionversion=c58dd2dd443c26d856a168db108a0cd11c285bf3 <9060abce3305ab2354c892c09d5689df51486df5
  7. Affected versionversion=c58dd2dd443c26d856a168db108a0cd11c285bf3 <cda0e0243bd3c04008fcd37a46b0269fb3c49249
  8. Affected versionversion=c58dd2dd443c26d856a168db108a0cd11c285bf3 <dbb3cbbf03b3c52cb390fabec357f1e4638004f5
  9. Affected versionversion=c58dd2dd443c26d856a168db108a0cd11c285bf3 <e58a171d35e32e6e8c37cfe0e8a94406732a331f
  10. Affected versionversion=c5e4ef499cfc78de45a4f01b8c557b5964d77c53
  11. Affected versionversion=f34728610b2a8c7b9864f9404f2884c17f6fca5c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.15; version=8b5740915a9faa8b1fa9166193a33e2a9ae30ec6; version=8ed40c122919cd79bc3c059e5864e5e7d9d455f0; version=a3bc0f8ea439762aa62d40a295157410498cbea7; version=c58dd2dd443c26d856a168db108a0cd11c285bf3 <3dd6ac973351308d4117eda32298a9f1d68764fd; version=c58dd2dd443c26d856a168db108a0cd11c285bf3 <9060abce3305ab2354c892c09d5689df51486df5; version=c58dd2dd443c26d856a168db108a0cd11c285bf3 <cda0e0243bd3c04008fcd37a46b0269fb3c49249; version=c58dd2dd443c26d856a168db108a0cd11c285bf3 <dbb3cbbf03b3c52cb390fabec357f1e4638004f5; version=c58dd2dd443c26d856a168db108a0cd11c285bf3 <e58a171d35e32e6e8c37cfe0e8a94406732a331f; version=c5e4ef499cfc78de45a4f01b8c557b5964d77c53; version=f34728610b2a8c7b9864f9404f2884c17f6fca5c

Published CVSS scores

7.8kernel.orgCVSS: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

CWE-416Use After Free
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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