CVE-2026-74401: Linux kernel · dlm: fix add msg handle in send_queue ordered
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in d2248cb70c070f8f04762872772e155b59016f17 : patch Linux kernel as a priority.
Data as of 30 Oct 2026, 12:49 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 9.8 |
|---|
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in d2248cb70c070f8f04762872772e155b59016f17, ae9e534e502a0f48c12baf83608c5de0ff0eab11, 6369619f1b665f12d8c99cc6ff733c64eb08b22e +3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
Description
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.
References
- git.kernel.org/stable/c/482606fea302d8bab86901d7426c3716980d99a8 (opens in a new tab)
- git.kernel.org/stable/c/ae9e534e502a0f48c12baf83608c5de0ff0eab11 (opens in a new tab)
- git.kernel.org/stable/c/6369619f1b665f12d8c99cc6ff733c64eb08b22e (opens in a new tab)
- git.kernel.org/stable/c/712714f818d83373847874ab0f8e426be79296cf (opens in a new tab)
- git.kernel.org/stable/c/4d45250b1d22960f86d83245be188b16e456218b (opens in a new tab)
- git.kernel.org/stable/c/d2248cb70c070f8f04762872772e155b59016f17 (opens in a new tab)