VulnerabilityPublished 15 Aug 2026Updated 6 Nov 2026

CVE-2026-74395: Linux kernel · RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference

Affects Linux kernelSource CVE Database V5

Compare

Not known to be exploited · fixed in f345e744b6b087188cde2377da5cbe9713b61353 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 18:03 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in f345e744b6b087188cde2377da5cbe9713b61353, 7921821fc2b19c01588311f6e7468ae5b68b1f61, 5100febf8e9d6c8c5ba8dc6534c6a5e3376e5989 +5

Exploitation 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 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 7597385371425febdaa8c6a1da3625d4ffff16f5, < f345e744b6b087188cde2377da5cbe9713b61353	Fixed in f345e744b6b087188cde2377da5cbe9713b61353
LinuxLinux	Affected ≥ 7597385371425febdaa8c6a1da3625d4ffff16f5, < 7921821fc2b19c01588311f6e7468ae5b68b1f61	Fixed in 7921821fc2b19c01588311f6e7468ae5b68b1f61
LinuxLinux	Affected ≥ 7597385371425febdaa8c6a1da3625d4ffff16f5, < 5100febf8e9d6c8c5ba8dc6534c6a5e3376e5989	Fixed in 5100febf8e9d6c8c5ba8dc6534c6a5e3376e5989
LinuxLinux	Affected ≥ 7597385371425febdaa8c6a1da3625d4ffff16f5, < 1025dc2f7ba29b04b8687790fa91f9cd1a53141e	Fixed in 1025dc2f7ba29b04b8687790fa91f9cd1a53141e
LinuxLinux	Affected ≥ 7597385371425febdaa8c6a1da3625d4ffff16f5, < 78b9589fda266c71f0f9d0c858d4fa7381a890a5	Fixed in 78b9589fda266c71f0f9d0c858d4fa7381a890a5
LinuxLinux	Affected ≥ 7597385371425febdaa8c6a1da3625d4ffff16f5, < 43f8f7946814c8e5f464518246fdbc69b6e32326	Fixed in 43f8f7946814c8e5f464518246fdbc69b6e32326

AI-suggested

A fix is available and has been applied in the Linux kernel. Users should update to a fixed kernel version containing the commits identified by the provided fixedVersions hashes. No additional mitigation steps are indicated.

Description

A NULL pointer dereference vulnerability in the Linux kernel's RDMA/mlx5 driver was fixed. The flaw occurs in the devx subscribe-event unwind path when eventfd_ctx_fdget() fails, leading to a dereference of an uninitialized pointer. This can cause kernel crashes or instability. The issue was resolved by ensuring proper cleanup logic is only executed once per key, preventing the NULL dereference.

Impact

The vulnerability can lead to a NULL pointer dereference in kernel space, potentially causing kernel crashes or system instability. There is no indication of remote code execution or privilege escalation from the provided data. No known exploits in the wild have been reported.

Summary

CVE-2026-74395 addresses a NULL pointer dereference in the Linux kernel's RDMA/mlx5 driver related to the devx subscribe-event unwind path. Specifically, MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT() links event_sub into a sub_list before initializing fields used by the shared error path. If eventfd_ctx_fdget() fails, the unwind path dereferences event_sub->ev_file in uverbs_uobject_put() and calls subscribe_event_xa_dealloc() with an unset xa_key_level1, causing a NULL dereference. The fix enforces that subscribe_event_xa_dealloc() is called only once per key by adding devx_key_in_sub_list() and cleaning up only the last matching pending entry.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 18:03 UTC

Technical details

References

Community reviews

Related threats