CVE-2023-52628

Local privilege escalation via nft_exthdr stack overwrite

Published Mar 28, 2024 · Updated Aug 5, 2026

Out-of-bounds write in Linux nftables allows local users to corrupt kernel stack memory by installing and evaluating crafted rules. When priv->len is divisible by four, nft_exthdr writes a zero to dst[len / 4] past struct nft_regs because remainder clearing is unconditional. Reaching the path requires CAP_NET_ADMIN in a network namespace, which user namespaces can grant; corruption can crash the kernel or enable same-host privilege escalation.

CVSS severity7.8
High
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Linux nftables allows local users to corrupt kernel stack memory by installing and evaluating crafted rules. When priv->len is divisible by four, nft_exthdr writes a zero to dst[len / 4] past struct nft_regs because remainder clearing is unconditional. Reaching the path requires CAP_NET_ADMIN in a network namespace, which user namespaces can grant; corruption can crash the kernel or enable same-host privilege escalation.

The record

CVE
CVE-2023-52628
Published
Mar 28, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 28, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.1
  2. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <1ad7b189cc1411048434e8595ffcbe7873b71082
  3. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <28a97c43c9e32f437ebb8d6126f9bb7f3ca9521a
  4. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <a7d86a77c33ba1c357a7504341172cc1507f0698
  5. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <c8f292322ff16b9a2272a67de396c09a50e09dce
  6. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <cf39c4f77a773a547ac2bcf30ecdd303bb0c80cb
  7. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <d9ebfc0f21377690837ebbd119e679243e0099cc
  8. Affected versionversion=49499c3e6e18b7677a63316f3ff54a16533dc28f <fd94d9dadee58e09b49075240fe83423eb1dcd36

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.1; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <1ad7b189cc1411048434e8595ffcbe7873b71082; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <28a97c43c9e32f437ebb8d6126f9bb7f3ca9521a; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <a7d86a77c33ba1c357a7504341172cc1507f0698; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <c8f292322ff16b9a2272a67de396c09a50e09dce; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <cf39c4f77a773a547ac2bcf30ecdd303bb0c80cb; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <d9ebfc0f21377690837ebbd119e679243e0099cc; version=49499c3e6e18b7677a63316f3ff54a16533dc28f <fd94d9dadee58e09b49075240fe83423eb1dcd36

Published CVSS scores

7.1GitHub Advisory DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
7.8Linux kernel CVE teamCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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