CVE-2026-53218

Updated on 25 Jun 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Overview

About vulnerability

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.

Details

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Amazon Linux 2023 Planned
Debian 11 Planned
Debian 11 cloud Planned
Debian 12 Planned