Bug 2492739 (CVE-2026-53249) - CVE-2026-53249 kernel: ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options
Summary: CVE-2026-53249 kernel: ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options
Keywords:
Status: NEW
Alias: CVE-2026-53249
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-25 10:03 UTC by OSIDB Bzimport
Modified: 2026-06-26 08:53 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-06-25 10:03:12 UTC
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.


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