NVD Vulnerability Detail
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CVE-2026-53249
Summary

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.

Publication Date June 25, 2026, 6:16 p.m.
Registration Date June 27, 2026, 4:27 a.m.
Last Update June 25, 2026, 6:16 p.m.
Related information, measures and tools
Common Vulnerabilities List