CVE-2026-53218 Details
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.
A vulnerability in the Linux kernel's netfilter component related to the nft_exthdr register tracking has been addressed. The issue arose because the nft_exthdr_init function passed user-controlled length data to nft_parse_register_store, marking that many bytes in the register bitmap as initialized. However, when the F_PRESENT flag was set, the evaluation paths only wrote 1 byte or 4 bytes (in specific error scenarios), leaving registers beyond the first unwritten and allowing uninitialized stack data to persist. The vulnerability could be triggered if userspace requested excessive data while F_PRESENT was active.
Users can update to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for downloading the patched version are available on the Linux kernel's official website.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-908 | Use of Uninitialized Resource | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 4.11, < 5.10.259 >= 5.11, < 5.15.210 >= 5.16, < 6.1.176 >= 6.2, < 6.6.143 >= 6.7, < 6.12.94 >= 6.13, < 6.18.36 >= 6.19, < 7.0.13 7.1 rc1 7.1 rc2 7.1 rc3 7.1 rc4 7.1 rc5 7.1 rc6 7.1 rc7 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 8, 2026 | CVE Modified | kernel.org |
| Sep 8, 2026 | CVE Modified | siemens-SADP |
| Jul 2, 2026 | Initial Analysis | [email protected] |
| Jun 25, 2026 | New CVE Received | kernel.org |