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CVE-2026-74401

Updated on 15 Aug 2026

Severity

9.8 Critical severity

Details

CVSS score
9.8
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Links
NISTCIRCLRHELUbuntu

Overview

About vulnerability

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

dlm: fix add msg handle in send_queue ordered

In a benchmark scenario triggering a lot of requests that triggers a lot of DLM messages on the network it can be that the mh->seq is not ordered according the oldest seq number. This ordering is required by dlm_receive_ack as “before(mh->seq, seq)” will stop to check for older sequence numbers that are ordered in the tail of “node->send_queue”.

The side effects of not having it correct ordered regarding “before(mh->seq, seq)” are refcounting issues and use-after free.

I only was able to reproduce this issue in a experimental DLM branch and a user space DLM benchmark that uses io_uring. After changing this I don’t experienced any refcounting with the sending buffer issues anymore.

Details

Affected product:
AlmaLinux 9.2 ESU , Debian 10 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU
Affected packages:
linux @ 4.19.0 (+3 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 13 Released
13 kernels
  • 6.12.85-1
  • 6.12.86-1
  • 6.12.88-1
  • 6.12.74-2
  • 6.12.73-1
  • 6.12.63-1
  • 6.12.69-1
  • 6.12.74-1
  • 6.12.90-1
  • 6.12.90-2
  • 6.12.94-1
  • 6.12.95-1
  • 6.12.96-1
Ubuntu 24.04 Planned —
Ubuntu 24.04 AWS Planned —
Ubuntu 26.04 Released
1 kernel
  • 7.0.0-31.31