In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_exthdr: fix register tracking for F_PRESENT flag nft_exthdr_init() passes user-controlled priv->len to nft_parse_register_store(), which marks that many bytes in the register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT is set, the eval paths write only 1 byte (nft_reg_store8) or 4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4, registers beyond the first are never written, retaining uninitialized stack data from nft_regs. Bail out if userspace requests too much data when F_PRESENT is set.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237 cve-icon
https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031 cve-icon
https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134 cve-icon
https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495 cve-icon
https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53 cve-icon
https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6 cve-icon
https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f cve-icon
https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265 cve-icon
https://lore.kernel.org/linux-cve-announce/2026062505-CVE-2026-53218-d36e@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-53218 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-53218 cve-icon
History

Fri, 26 Jun 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-824
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Thu, 25 Jun 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-457

Thu, 25 Jun 2026 09:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_exthdr: fix register tracking for F_PRESENT flag nft_exthdr_init() passes user-controlled priv->len to nft_parse_register_store(), which marks that many bytes in the register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT is set, the eval paths write only 1 byte (nft_reg_store8) or 4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4, registers beyond the first are never written, retaining uninitialized stack data from nft_regs. Bail out if userspace requests too much data when F_PRESENT is set.
Title netfilter: nft_exthdr: fix register tracking for F_PRESENT flag
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-06-25T08:39:21.069Z

Updated: 2026-06-25T08:39:21.069Z

Reserved: 2026-06-09T07:44:35.392Z

Link: CVE-2026-53218

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-06-25T00:00:00Z

Links: CVE-2026-53218 - Bugzilla