CVE-2026-90054
kernel: tcp: fix corruption of urgent data on multi-segment retransmit
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 17, 2026
Updated · October 13, 2026
Description
A flaw was found in the Linux kernel's Transmission Control Protocol (TCP) urgent data handling. When TCP retransmits multi-segment packets while in urgent mode, the urgent pointer (urg_ptr) is incorrectly copied across segments. This error causes the receiver to misinterpret the urgent data's position, leading to the out-of-band data being processed as normal in-band data. Consequently, a remote attacker could exploit this to corrupt the TCP data stream.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 6.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
CWE-823 · Use of Out-of-range Pointer Offset