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 0.0007
EPSS Percentile 20.9%
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 (20)
Linux/Linux < 2.6.12
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 07a9b32eaae792ff7d0fcac14d8920c937c0a9c3
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 5e13d0a37666955b6cfddc0f73cb40ed645b8a05
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 735ee8582da3d239eb0c7a53adca61b79fb228b3
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 8b300f726640c48c3edfe9c453334dd801f4b74e
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - cd5beda7e0e32865e214f28034bb92c1cecff885
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - eaedc0bc18be46fe7f58170e967959a932c4f824
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - f6c412dcfd76b0516d51aa847d8f4c7b70381b09
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - f895191dc32c53eaf443b6443fe40945b2f92287
Linux/Linux 2.6.12
... and 10 more
Published May 06, 2026
Tracked Since May 06, 2026