CVE intelligence

CVE-2026-31420

Vulnerability intelligence

Published Apr 13, 2026Sources checked Oct 27, 2026

5.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-31420 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Oct 8, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - ARM64 architecture; - ARM32 architecture; - MIPS architecture; - PowerPC architecture; - x86 architecture; - Intel NPU Driver; - Compute Acceleration Framework; - Auxiliary display drivers; - Drivers core; - Compressed RAM block device driver; - Bluetooth drivers; - Arm Firmware Framework for ARMv8-A(FFA); - EFI core; - GPIO subsystem; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - I2C subsystem; - IIO subsystem; - InfiniBand drivers; - Input Device core drivers; - Input Device (Mouse) drivers; - Multiple devices driver; - Media drivers; - Fastrpc Driver; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Microsoft Azure Network Adapter (MANA) driver; - Texas Instruments network drivers; -

Ubuntu Security Notices guidance

Vendor revision: Sep 29, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - ARM32 architecture; - ARM64 architecture; - PowerPC architecture; - Compute Acceleration Framework; - Drivers core; - Bluetooth drivers; - Arm Firmware Framework for ARMv8-A(FFA); - EFI core; - GPU drivers; - Hardware monitoring drivers; - InfiniBand drivers; - Network drivers; - Microsoft Azure Network Adapter (MANA) driver; - SCSI subsystem; - SPI subsystem; - Network file systems library; - NTFS3 file system; - SMB network file system; - File systems infrastructure; - Software nodes and device properties; - Bluetooth subsystem; - Netfilter; - Tracing infrastructure; - io_uring subsystem; - IRQ subsystem; - KProbes tracing; - Memory management; - B.A.T.M.A.N.

Ubuntu Security Notices guidance

Vendor revision: Sep 25, 2026

Vendor remediation details

CISA KEVNot listedBased on the latest collected catalog

EPSS0.1%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-31420?

In the Linux kernel, the following vulnerability has been resolved:

bridge: mrp: reject zero test interval to avoid OOM panic

br_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied interval value from netlink without validation. When interval is 0, usecs_to_jiffies(0) yields 0, causing the delayed work (br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule itself with zero delay.

This creates a tight loop on system_percpu_wq that allocates and transmits MRP test frames at maximum rate, exhausting all system memory and causing a kernel panic via OOM deadlock.

The same zero-interval issue applies to br_mrp_start_in_test_parse() for interconnect test frames.

Use NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both IFLA_BRIDGE_MRP_START_TEST_INTERVAL and IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the netlink attribute parsing layer before the value ever reaches the workqueue scheduling code. This is consistent with how other bridge subsystems (br_fdb, br_mst) enforce range constraints on netlink attributes.

Source: NVD