CVE-2026-53249

In the Linux kernel, the following vulnerability has been resolved:

ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options

This patch restricts setting Loose Source and Record Route (LSRR)

and Strict Source and Record Route (SSRR) IP options to users

with CAP_NET_RAW capability.

This prevents unprivileged applications from forcing packets to route

through attacker-controlled nodes to leak TCP ISN and possibly other

protocol information.

While LSRR and SSRR are commonly filtered in many network environments,

they may still be supported and forwarded along some network paths.

RFC 7126 (Recommendations on Filtering of IPv4 Packets Containing

IPv4 Options) recommend to drop these options in 4.3 and 4.4.