According to Security NEXT, a use-after-free vulnerability (CVE-2026-98432) exists in IPv4 TCP connection handling in the Linux kernel [1]. A race condition during connection establishment can cause memory still referenced by other processes to be freed, allowing specially crafted packets with IP options to cause system crashes, memory disclosure, or memory corruption [1]. The Linux Kernel Organization assigned a CVSS v3 score of 9.8 (Critical), distributions are rolling out fixes, and the report also noted proof-of-concept activity in specific environments [1].
This event has not been officially confirmed. Content is based on media or third-party reports.
Critical Memory Vulnerability Discovered in Linux Kernel TCP Connection Handling
1 min read
- Disclosed
- Nov 4, 2026
- Published
- Nov 11, 2026
- Last updated
- Nov 8, 2026
- CVSS basis
- [1]
- 0.8%, higher than 56% of CVEs
- Exploitation and patch status
- Patch available
- Attack vector
- Vulnerability status
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Technology
What to do nowOur advice
The Linux Kernel Organization assigned a CVSS v3 score of 9.8 (Critical), distributions are rolling out fixes, and the report also noted proof-of-concept activity in specific environments [1].
Timeline
- Security NEXT publishes report (date only; timestamp is a placeholder)[1]
- iThome reports multiple Linux distributions rolling out patches for CVE-2026-98432 while some versions remain pending[2]
According to iThome, CVE-2026-98432 affects Linux kernel versions 4.4 and later, allowing remote attackers to execute arbitrary commands as root on servers with MPTCP listeners enabled; patches have been released for AlmaLinux, Amazon Linux, Debian (select branches), Oracle Linux, Red Hat Enterprise Linux, Rocky Linux, and select SUSE versions, while fixes for Ubuntu 26.04, 24.04, and 22.04 LTS remain in progress.
Technical details
Verified Source Summary
A use-after-free vulnerability (CVE-2026-98432) exists in IPv4 TCP connection handling in the Linux kernel [1].
A race condition during connection establishment can cause memory still referenced by other processes to be freed, allowing specially crafted packets with IP options to cause system crashes, memory disclosure, or memory corruption [1].
The Linux Kernel Organization assigned a v3 score of 9.8 (Critical), distributions are rolling out fixes, and the report also noted proof-of-concept activity in specific environments [1].
References
Media2
- [1]
“「Linuxカーネル」のTCP接続処理に深刻な脆弱性が判明した。ディストリビューターが修正に向けた対応を順次進めている。特定環境における実証なども報告されている。”
- [2]
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