CVE-2026-53249

NameCVE-2026-53249
DescriptionIn 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4664-1, DLA-4665-1, DLA-4671-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1vulnerable
bullseye (security)5.10.259-1fixed
bookworm, bookworm (security)6.1.176-1fixed
trixie6.12.94-1fixed
trixie (security)6.12.95-1fixed
forky, sid7.1.3-1fixed
linux-6.1 (PTS)bullseye (security)6.1.176-1~deb11u1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebullseye5.10.259-1DLA-4664-1
linuxsourcebookworm6.1.176-1DLA-4665-1
linuxsourcetrixie6.12.94-1
linuxsource(unstable)7.0.13-1
linux-6.1sourcebullseye6.1.176-1~deb11u1DLA-4671-1

Notes

https://git.kernel.org/linus/d3915a1f5a4bc0ac911032903c3c6ab8df9fcc7c (7.1-rc7)

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