Critical severity · published Aug 15, 2026
CVE-2026-74401
dlm: fix add msg handle in send_queue ordered
9.8
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 51% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
489d8e559c6596eb08e16447d9830bc39afbe54e before ae9e534e502a0f48c12baf83608c5de0ff0eab11; 489d8e559c6596eb08e16447d9830bc39afbe54e before 6369619f1b665f12d8c99cc6ff733c64eb08b22e; 489d8e559c6596eb08e16447d9830bc39afbe54e before 712714f818d83373847874ab0f8e426be79296cf; 489d8e559c6596eb08e16447d9830bc39afbe54e before 4d45250b1d22960f86d83245be188b16e456218b; 489d8e559c6596eb08e16447d9830bc39afbe54e before d2248cb70c070f8f04762872772e155b59016f17; 5.14 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-74401
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-74401
git.kernel.org
https://git.kernel.org/stable/c/4d45250b1d22960f86d83245be188b16e456218b
git.kernel.org
https://git.kernel.org/stable/c/6369619f1b665f12d8c99cc6ff733c64eb08b22e
git.kernel.org
https://git.kernel.org/stable/c/712714f818d83373847874ab0f8e426be79296cf
git.kernel.org
https://git.kernel.org/stable/c/ae9e534e502a0f48c12baf83608c5de0ff0eab11
git.kernel.org
https://git.kernel.org/stable/c/d2248cb70c070f8f04762872772e155b59016f17
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