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[[Linux-announce] ] Linux kernel vulnerabilities in network code

From: "Konrad Bucheli (PSI)" <konrad.bucheli AT psi.ch>
To: linux-announce AT lists.psi.ch
Subject: [[Linux-announce] ] Linux kernel vulnerabilities in network code
Date: Mon, 2 Nov 2026 15:55:15 +0100
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Dear Linux admins

We have two kernel vulnerabilities which require attention:

First there is "use-after-free on socket options" (CVE-2026-98432 [1]) which can cause kernel memory corruption and denial of service. There are now patched kernel available for RHEL8 and RHEL9.

Second "buffer underflow in skb_zerocopy" (CVE-2026-68123 [2]) can also cause memory corruption, but is rated less severe by RedHat as exploitation requires "Open vSwitch userspace action path under specific, complex conditions". So is is only of importance if Open vSwitch is in use.

Following kernel fixes are now available:

RHEL9: kernel-5.14.0-687.64.1.el9_8 fixes both vulnerabilities
RHEL8: kernel-4.18.0-553.182.1.el8_10 fixes "use-after-free", but not "skb_zerocopy" yet

Please consider updating your kernels ASAP, eg. with

dnf update --refresh --assumeyes

and then, this is important: reboot.

Kind regards
Konrad

[1] https://access.redhat.com/security/cve/cve-2026-98432
[2] https://access.redhat.com/security/cve/cve-2026-68123

--
Paul Scherrer Institut
Konrad Bucheli
Linux Systems Engineer
Core Linux Research Services
Science IT Infrastructure and Services department (AWI)
OBBA/230
Forschungstrasse 111
5232 Villigen PSI
Switzerland

Phone: +41 56 310 27 24
konrad.bucheli AT psi.ch
www.psi.ch

[[Linux-announce] ] Linux kernel vulnerabilities in network code, Konrad Bucheli (PSI), 11/02/2026