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Linux Kernel CVE-2026-93151

| EUVDEUVD-2026-82259 HIGH
2026-09-17 Linux GHSA-fxwv-gg7j-r6jf
7.5
CVSS 3.1 · Vendor: Linux
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Access RDMA fabric / target host
  2. Delivery
    Establish NVMe-oF RDMA connection with in-flight I/O
  3. Exploit
    Force queue/QP teardown (target removal or connection drop)
  4. Execution
    Leak per-response rw-context and request SGLs
  5. Persist
    Repeat cycles to exhaust kernel memory
  6. Impact
    Target host degradation/crash (DoS)

Vulnerability Assessment

Exploitation Conditions

Requires the target host to run the Linux NVMe-oF target stack with the RDMA transport (nvmet-rdma) actively serving connections over an RDMA-capable fabric (hardware RDMA NIC or the siw software-iWARP driver, as used in the blktests nvme/061 reproducer). The leak is triggered specifically when a queue/QP is torn down - e.g., the target is removed or the RDMA connection is disrupted - while NVMe I/O responses are still in flight, so their send completions are never delivered. Limiting factors: the subsystem must be configured and in use (default installs do not run an NVMe-oF RDMA target), each event leaks only small allocations so impact requires many repeated teardown cycles to exhaust memory, and no confidentiality/integrity impact exists (availability only). No user interaction is required.

Impact

This is a kernel memory leak in the NVMe-oF RDMA target (nvmet-rdma), not a memory-corruption or disclosure bug. The vendor CVSS is 7.5 with vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - the C:N/I:N confirms there is no confidentiality or integrity impact, so the 'Information Disclosure' tag is contradicted by the vendor's own vector and is mislabeled; the only impact is availability (A:H) via gradual memory exhaustion. The AV:N/AC:L/PR:N portion appears overstated: the leak is triggered on queue/QP teardown when an RDMA target is removed while I/Os are in flight (the description and kmemleak backtrace show it reproduced via blktests nvme/061 over the siw software RDMA driver), which is an administrative/teardown event rather than a clean remote-unauthenticated code path an outside attacker directly drives, and a single occurrence leaks only small SGL/rw-context allocations (32-64 bytes) so exhaustion requires many repeated teardown cycles. There is NO EPSS score, NO CISA KEV listing, and NO public POC in the provided data - exploitation status is 'no public exploit identified at time of analysis'. Net: a real but low-urgency reliability/DoS bug in a niche subsystem; the headline 7.5 overstates practical risk. Conflicting signal to verify: CVSS asserts network vector with no privileges, but the described trigger (target removal / connection teardown during in-flight I/O) implies local/administrative involvement - verify the true attacker-reachability with the maintainer.

Exploit ScenarioDerived

An operator or fault removes/tears down an nvmet-rdma target (or an RDMA connection drops) while NVMe-oF clients have I/Os in flight; responses whose send completions never fire skip nvmet_rdma_send_done()/release_rsp(), permanently leaking their RDMA read/write contexts and request SGLs. Repeated connect/teardown cycles under load slowly exhaust kernel memory, degrading or crashing the storage target host. No public exploit code is identified, and the effect is a gradual resource leak rather than instantaneous compromise.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Sep 18, 2026

Unreleased RDMA response resources leak kernel memory in the Linux kernel's NVMe-over-Fabrics RDMA target (nvmet-rdma) when a queue pair is torn down while I/O responses are still in flight, so their send completions never fire and the associated rdma_rw contexts and request SGLs are never freed. The issue affects kernels since the RDMA target transport appeared (reported as far back as Linux 4.8) and is triggered by removing the target, resetting the RDMA connection, or otherwise dismantling a queue with outstanding responses - an operation reachable by a local actor holding low privileges on the target host (CVSS:3.1/AV:L/AC:H/PR:L/UI:N). Impact is availability-only and accumulates slowly, since each teardown leaks only small allocations and many repeated cycles are needed to exhaust memory; no public exploit code or active exploitation has been identified at time of analysis, and vendor patch releases are available.

RemediationAI

Vendor-released patch: upgrade to Linux 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.52, or 7.2.6 (mainline 7.3-rc1), each carrying the fix that calls nvmet_rdma_free_rsp_resources() during QP teardown; the individual stable commits are linked from https://git.kernel.org/stable/c/91cfa74f1f3772e8c3662c064a45d8633e00c78e and the other git.kernel.org/stable/c references, with the NVD entry at https://nvd.nist.gov/vuln/detail/CVE-2026-93151. If immediate kernel upgrade is not possible, the actionable mitigations carry real trade-offs: quiesce and drain NVMe-oF I/O before removing an RDMA target or issuing an abrupt nvme disconnect/link reset, since the leak only occurs when responses are in flight at teardown (this reduces but does not eliminate exposure under link-failure conditions); stop the RDMA transport entirely and use nvmet-tcp or another fabric instead, which removes the vulnerable code path at the cost of losing RDMA offload performance and requiring client-side reconfiguration; restrict who can administer the NVMe-oF target and RDMA fabric so untrusted local actors cannot repeatedly force queue teardowns, accepting that this is a privilege-restriction control rather than a fix; and monitor for the leak by watching kmalloc activity and, where available, kmemleak or slab growth for allocations attributed to sgl_alloc_order, rdma_rw_ctx_init, and nvmet_rdma_map_sgl_keyed so that unpatched hosts can be rebooted before memory pressure becomes disruptive. Note that this is a gradual availability-only leak - there is no data corruption or disclosure to mitigate - and no public exploit code was identified at time of analysis, so patching can be scheduled through normal maintenance rather than emergency change control.

Affected VersionsENISA

Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <156ec10a8be2c33b0c279d8b2f4fe8e16fa89ef7
Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <9584b3c30e4ee8ca315bdc12249cc6c47cf1a482
Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <91cfa74f1f3772e8c3662c064a45d8633e00c78e
Linux patch: 7.3-rc1
Linux patch: 6.12.110
Linux patch: 6.6.157
Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <ca795fc1d8a1a4ab0e6bd1d27c9adb78d4ed1a1c
Linux 4.8
Linux patch: 6.18.52
Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <d553a9dc1c45666e76d8d2ac9a4f8ff0cbf53a50
Linux patch: 7.2.6
Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <0114dd303b373522dea06053aabae34bdd33a7c4
Linux patch: 5.15.221
Linux 8f000cac6e7a6edca7ab93bafc7ed28b27c1545b <5cc3b21729d45b5af8f79891f9dedb7e6b6dbd08
Linux patch: 0
Linux patch: 6.1.188

Affected Packages

euvd linux no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

nvmet-rdma is the RDMA transport implementation of the in-kernel NVMe-over-Fabrics target, layered on the Linux RDMA subsystem (ib_core) and usable over hardware RDMA NICs or the software siw/iWARP driver. When the target maps an NVMe command for transmission, nvmet_rdma_map_sgl_keyed() allocates request scatter-gather lists through nvmet_req_alloc_sgls()/sgl_alloc_order() and builds RDMA read/write contexts via rdma_rw_ctx_init(); these resources are normally released in the response completion path, nvmet_rdma_send_done() and nvmet_rdma_release_rsp(). If the queue's QP is destroyed before the send completion for an in-flight response is delivered, that free path never executes and the allocations become unreachable - kmemleak traces in the report originate from kworker context inside __ib_process_cq()/ib_cq_poll_work() calling nvmet_rdma_handle_command(), confirming the leak sites are the SGL and rdma_rw_ctx allocations. The upstream input does not assign a CWE, but the root-cause class is a missing-release-of-memory-resource leak (CWE-401-like), not memory corruption or disclosure. The fix reclaims in-flight response memory during QP teardown by invoking nvmet_rdma_free_rsp_resources(), which frees the RDMA read/write context and SGLs for responses whose completions will never arrive. Note that the CNA-style CVSS of 7.5 (AV:N) overstates the practical exploitability relative to our assessment, which treats the trigger as local, high-complexity, low-privilege, with only a low availability impact.

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Severity by source

Vendor (Linux) PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vuln.today AI 2.5 LOW

Trigger is target/queue teardown during in-flight I/O (local/admin-adjacent, race-like → AV:L/AC:H/PR:L); slow small-allocation leak yields only gradual availability degradation (A:L), no C/I impact.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
4.0 AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
SUSE 3.1 MEDIUM
AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
Red Hat 5.5 MEDIUM

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

4
CVSS changed
Sep 18, 2026 - 18:22 NVD
7.5 (HIGH)
Patch available
Sep 17, 2026 - 17:19 EUVD
CVE Published
Sep 17, 2026 - 16:11 cve.org
UNKNOWN (no severity yet)
CVE Published
Sep 17, 2026 - 16:11 cve.org
HIGH 7.5

DescriptionCVE.org

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

nvmet-rdma: fix response resource leak on queue teardown

When an nvme target with rdma transport is removed while I/Os are in flight, a response can be posted but its send completion is never delivered before the connection is torn down. As a result nvmet_rdma_send_done() and nvmet_rdma_release_rsp() are never called for the response, and this leaks the allocated RDMA read/write context and request SGLs.

These leaks are recreated by running blktests nvme/061 with the rdma transport and the siw driver. Kernel kmemleak feature reports them as follows:

unreferenced object 0xffff88812bc490c0 (size 32): comm "kworker/2:1H", pid 409, jiffies 4307744490 backtrace (crc 89afd339): __kmalloc_noprof+0x5f9/0x890 sgl_alloc_order+0x7b/0x380 nvmet_req_alloc_sgls+0x290/0x4f0 [nvmet] nvmet_rdma_map_sgl_keyed+0x241/0x12e0 [nvmet_rdma] nvmet_rdma_handle_command+0x73e/0xb80 [nvmet_rdma] __ib_process_cq+0x149/0x4c0 [ib_core] ib_cq_poll_work+0x49/0x160 [ib_core] process_one_work+0x8b2/0x1640 worker_thread+0x5fd/0xfe0 kthread+0x367/0x460 ret_from_fork+0x655/0x9d0 ret_from_fork_asm+0x1a/0x30

unreferenced object 0xffff88814bd05e80 (size 64): comm "kworker/3:1H", pid 148, jiffies 4295195428 backtrace (crc e35510cb): __kmalloc_noprof+0x5f9/0x890 rdma_rw_ctx_init+0x333/0x1fa0 [ib_core] nvmet_rdma_map_sgl_keyed+0x5c8/0x12e0 [nvmet_rdma] nvmet_rdma_handle_command+0x73e/0xb80 [nvmet_rdma] __ib_process_cq+0x149/0x4c0 [ib_core] ib_cq_poll_work+0x49/0x160 [ib_core] process_one_work+0x8b2/0x1640 worker_thread+0x5fd/0xfe0 kthread+0x367/0x460 ret_from_fork+0x655/0x9d0 ret_from_fork_asm+0x1a/0x30

To avoid the memory leaks, reclaim the memory of the in-flight responses when the queue QP is torn down. Call nvmet_rdma_free_rsp_resources() that frees up the RDMA read/write context and the request SGLs of such responses.

Executive ViewAI

Why It Matters

The Linux kernel's NVMe-over-Fabrics RDMA target (nvmet-rdma) contains a memory leak that local users with low privileges can trigger, gradually degrading availability on affected storage hosts. Although exploitation requires a specific teardown condition and no public exploit identified at time of analysis, unpatched RDMA-enabled NVMe-oF targets in production could experience memory exhaustion over time, disrupting storage services. Leadership should prioritize patching because the affected component sits in the data path for high-performance storage fabrics.

Business Impact: Medium
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
0.2%
Top 89% exploitable
Prevalence
Low
NVMe-oF RDMA target (nvmet-rdma) is niche datacenter/storage-fabric functionality
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.2%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
Medium

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
openSUSE Tumbleweed Fixed
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected

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