Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-23254

 

Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-23254

Published: March 20, 2026


Vulnerability identifier: #VU124194
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23254
CWE-ID: CWE-754
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper input validation in the UDP GRO complete stage when handling network packets. A remote attacker can send specially crafted network packets to cause a denial of service.

The issue arises because the udp4_gro_complete() function uses an incorrect network offset to compute the outer UDP header pseudo checksum when the 'encapsulation' flag is set, leading to checksum validation errors and subsequent packet processing failures.


Affected software

Linux kernel
Ubuntu
openEuler
python3-perf-debuginfo
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
kernel-source
kernel-extra-modules
linux-fips (Ubuntu package)
linux (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-6.8 (Ubuntu package)
linux-azure (Ubuntu package)

How to mitigate CVE-2026-23254

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debugsource - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-headers - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-source - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-extra-modules - update to 6.6.0-145.0.2.143
linux-fips (Ubuntu package) - update to 6.8.0-116.116+fips1
linux (Ubuntu package) - addressed in versions 6.8.0-117.117, 6.8.0-117.117.1, 6.8.0-117.117.1~22.04.1, 6.8.0-1041.44, 6.8.0-1054.60, 6.8.0-1055.56, 6.8.0-1055.56~22.04.1, 6.8.0-1055.58+fips1, 6.8.0-1056.60, 6.8.0-1058.61, 6.8.0-1058.61+fips1, 6.8.0-2045.46, 6.8.1-1051.52, 6.8.1-1051.52~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1024.24
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1054.57, 6.8.0-1054.57.1
linux-nvidia-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - update to 6.8.0-1056.62

External References

Related Security Bulletins