PT-2026-52313 · Linux · Linux

Published 2026-06-25 · Updated 2026-06-25 · CVE-2026-53218

NVD

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.

Related Identifiers

CVE-2026-53218

Affected Products

Linux

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2026-53218 · Security Note
• https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265 · Note
• https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f · Note
• https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134 · Note
• https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495 · Note
• https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237 · Note
• https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031 · Note
• https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53 · Note
• https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6 · Note