Memory leak in Linux kernel - CVE-2026-31610

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Main Vulnerability Database Vulnerabilities #VU127782

Memory leak in Linux kernel - CVE-2026-31610

Published: April 25, 2026


Vulnerability identifier: #VU127782
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-31610
CWE-ID: CWE-401
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 a memory leak in smb2_sess_setup() SPNEGO negotiation handling when processing a malformed SPNEGO negotiation token. A remote attacker can send a specially crafted negotiation blob to cause a denial of service.

The issue is reachable pre-authentication, and malformed later elements in the same token can leave an allocated mechToken uncleared after both SPNEGO grammars fail.


Affected software

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-kvm (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-lowlatency-hwe-5.15 (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-fips (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-realtime (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-intel-iotg-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-xilinx-zynqmp (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-raspi (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux (Debian package)

How to mitigate CVE-2026-31610

Install security update from vendor's repository.

linux (Ubuntu package) - addressed in versions 5.15.0-198.208, 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72~22.04.1, 6.8.0-1064.72, 6.8.1-1056.57~22.04.2, 6.8.1-1056.57, 7.0.0-27.27
linux-kvm (Ubuntu package) - update to 5.15.0-1109.114
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 7.0.0-1007.7
linux-aws (Ubuntu package) - addressed in versions 5.15.0-1117.124, 6.8.0-1061.64+1, 7.0.0-1008.8
linux-azure (Ubuntu package) - addressed in versions 5.15.0-1123.132, 6.8.0-1063.71~22.04.1, 6.8.0-1063.71, 7.0.0-1010.10
linux-oracle (Ubuntu package) - addressed in versions 5.15.0-1114.120, 7.0.0-1007.7
linux-lowlatency (Ubuntu package) - update to 5.15.0-195.205
linux-gke (Ubuntu package) - update to 5.15.0-1113.119
linux-aws-5.15 (Ubuntu package) - update to 5.15.0-1117.124~20.04.1
linux-lowlatency-hwe-5.15 (Ubuntu package) - update to 5.15.0-195.205~20.04.1
linux-hwe-5.15 (Ubuntu package) - update to 5.15.0-198.208~20.04.1
linux-fips (Ubuntu package) - addressed in versions 5.15.0-198.208+fips1, 6.8.0-136.136+fips2, 6.8.0-136.136.2~22.04.1, 6.8.0-136.136.2, 6.8.0-1058.61
linux-azure-5.15 (Ubuntu package) - update to 5.15.0-1123.132~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1111.115~20.04.1
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-intel-iotg (Ubuntu package) - update to 5.15.0-1112.118
linux-gkeop (Ubuntu package) - update to 5.15.0-1100.108
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-realtime (Ubuntu package) - addressed in versions 5.15.0-1116.125, 7.0.0-27.27.1
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 6.8.0-1059.62~22.04.1, 6.8.0-1059.62, 6.8.0-1059.62.1, 7.0.0-1013.13
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1122.131~20.04.1
linux-ibm (Ubuntu package) - addressed in versions 5.15.0-1111.115, 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62~22.04.1, 6.8.0-1061.62, 7.0.0-1009.9
linux-intel-iotg-5.15 (Ubuntu package) - update to 5.15.0-1112.118~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1118.128~20.04.1
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1122.131, 6.8.0-1062.69, 7.0.0-1009.9
linux-xilinx-zynqmp (Ubuntu package) - update to 5.15.0-1080.84
linux-intel-iot-realtime (Ubuntu package) - update to 5.15.0-1109.111
linux-gcp-fips (Ubuntu package) - addressed in versions 5.15.0-1118.128+fips1, 6.8.0-1064.72+fips1
linux-aws-fips (Ubuntu package) - update to 5.15.0-1117.124+fips1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0-1123.132+fips1, 6.8.0-1063.71+fips2
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52, 7.0.0-1014.14
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64~22.04.1, 6.8.0-1061.64+fips1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux (Debian package) - update to 6.12.85-1

External References

Related Security Bulletins