CVE-2026-43190

HIGH

netfilter: xt_tcpmss: check remaining length before reading optlen

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting reporter: In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads op[i+1] directly without validating the remaining option length. If the last byte of the option field is not EOL/NOP (0/1), the code attempts to index op[i+1]. In the case where i + 1 == optlen, this causes an out-of-bounds read, accessing memory past the optlen boundary (either reading beyond the stack buffer _opt or the following payload).

Scores

CVSS v3 8.2
EPSS 0.0046
EPSS Percentile 37.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Details

CWE
CWE-125
Status published
Products (27)
linux/Kernel 2.6.12 - 5.10.252linux
linux/Kernel 5.11.0 - 5.15.202linux
linux/Kernel 5.16.0 - 6.1.165linux
linux/Kernel 6.13.0 - 6.18.16linux
linux/Kernel 6.19.0 - 6.19.6linux
linux/Kernel 6.2.0 - 6.6.128linux
linux/Kernel 6.7.0 - 6.12.75linux
Linux/Linux < 2.6.12
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 07a9b32eaae792ff7d0fcac14d8920c937c0a9c3
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 5e13d0a37666955b6cfddc0f73cb40ed645b8a05
... and 17 more
Published May 06, 2026
Tracked Since May 06, 2026