CVE-2026-74395 — RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT() links event_sub into sub_list before initializing the fields used by the shared error path. If eventfd_ctx_fdget() then 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. subscribe_event_xa_alloc() creates the XA entry exactly once for a given key_level1, on the first occurrence of that key. The unwind path must therefore call subscribe_event_xa_dealloc() exactly once for it as well. Enforce that by adding devx_key_in_sub_list() and calling subscribe_event_xa_dealloc() only when the last matching pending entry is being cleaned up.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 6e15b770461eeaa0ff73934922cb670a6a9db04e≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 9be9aca28424228586fe9211c373ebdb826ebb6c≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < f345e744b6b087188cde2377da5cbe9713b61353≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 1025dc2f7ba29b04b8687790fa91f9cd1a53141e≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 7921821fc2b19c01588311f6e7468ae5b68b1f61≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 5100febf8e9d6c8c5ba8dc6534c6a5e3376e5989≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 78b9589fda266c71f0f9d0c858d4fa7381a890a5≥ 7597385371425febdaa8c6a1da3625d4ffff16f5 and < 43f8f7946814c8e5f464518246fdbc69b6e32326 and 1 moreversion 5.3 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 29, 2026 · 14 reading(s) · max 0.22%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/43f8f7946814c8e5f464518246fdbc69b6e32326
- git.kernel.org/stable/c/7921821fc2b19c01588311f6e7468ae5b68b1f61
- git.kernel.org/stable/c/f345e744b6b087188cde2377da5cbe9713b61353
- git.kernel.org/stable/c/5100febf8e9d6c8c5ba8dc6534c6a5e3376e5989
- git.kernel.org/stable/c/78b9589fda266c71f0f9d0c858d4fa7381a890a5
- git.kernel.org/stable/c/9be9aca28424228586fe9211c373ebdb826ebb6c
- git.kernel.org/stable/c/6e15b770461eeaa0ff73934922cb670a6a9db04e
- git.kernel.org/stable/c/1025dc2f7ba29b04b8687790fa91f9cd1a53141e
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-74395 is "RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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