CVE-2026-43190: Linux Kernel

High severity, CVSS 8.2. EPSS: 0.5% chance of exploitation in the next 30 days.

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).

Affected products

• Linux Linux Kernel: from 2.6.12.1, before 5.10.252 (fixed in 5.10.252); from 5.11, before 5.15.202 (fixed in 5.15.202); from 5.16, before 6.1.165 (fixed in 6.1.165); from 6.2, before 6.6.128 (fixed in 6.6.128); from 6.7, before 6.12.75 (fixed in 6.12.75); from 6.13, before 6.18.16 (fixed in 6.18.16); …

Published 2026-05-06. Last modified 2026-06-17.