EUVD-2026-12896Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Resource cleanup, leak prevention
|
| Impact | While formal CVSS and EPSS scores are not provided in the intelligence data, this vulnerability presents moderate real-world risk with strong mitigating factors. The attack vector requires local access or the ability to trigger NVMe/FC controller initialization (medium to high complexity), and successful exploitation results in memory exhaustion leading to denial of service rather than code execution or data exfiltration. The vulnerability is not tracked in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating no active exploitation in the wild. However, the fix is already available across five stable kernel branches (commits visible in git.kernel.org references), and the leak is reproducible via blktests nvme/fc test suite. For systems running vulnerable kernel versions with NVMe/FC hardware, this represents a medium-priority reliability issue suitable for standard patch management cycles. The lack of remote exploitability and availability of patches reduces urgency compared to high-impact vulnerabilities, but deployment should follow normal security patching schedules. |
| Exploit ScenarioDerived | A local attacker with the ability to trigger device creation operations (such as through privileged container escape or local privilege escalation) could repeatedly attempt to create and fail NVMe/FC controller connections through the nvmf_dev_write interface. With each failed initialization after the admin queue allocation, a block I/O tag set remains leaked in kernel memory. After sufficient iterations, cumulative memory exhaustion causes the system to become unresponsive or crash due to out-of-memory conditions, achieving denial of service. No public proof-of-concept exploit exists beyond the reproducible kmemleak detection via blktests nvme/fc, indicating the attack requires either NVMe/FC hardware or kernel module instrumentation. |
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Alert meAnalysisAIv1 – Mar 18, 2026
This vulnerability is a resource leak in the Linux kernel's NVMe/FC (NVMe over Fibre Channel) driver where the admin tag set and associated block I/O queue resources fail to be released if controller initialization encounters errors after the admin queue is allocated. The affected product is the Linux kernel across all versions that include the vulnerable nvme-fc code path. An attacker or malicious process could trigger repeated failed NVMe/FC controller initialization attempts to exhaust kernel memory through cumulative tag set leaks, potentially leading to denial of service. This is not actively exploited in the wild (not listed in CISA KEV), but patches are available across multiple kernel branches.
RemediationAI
Apply kernel updates that include the nvme-fc admin tag set cleanup patch. Users should upgrade to a kernel version containing one of the five commits referenced in the git.kernel.org/stable repository (commit hashes provided above). Check your Linux distribution's security advisory pages (e.g., kernel.org, Ubuntu Security Notices, Red Hat Security Advisories, SUSE Security Updates) for specific kernel versions that incorporate these fixes. For systems where immediate kernel patching is not feasible, restrict NVMe/FC controller initialization attempts and monitor kernel memory usage via /proc/meminfo and dmesg for repeated kmemleak warnings related to nvme-fc tag set allocations. If systems are not actively using NVMe/FC hardware, consider disabling the nvme-fc module at boot time via kernel command-line parameters until patching can be completed.
Affected VersionsENISA
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Technical ContextAI · show details
The vulnerability resides in the NVMe/FC (Non-Volatile Memory Express over Fibre Channel) subsystem of the Linux kernel, specifically in the nvme_fc_init_ctrl() function called during controller creation via the nvmf_dev_write()->nvmf_create_ctrl()->nvme_fc_create_ctrl() call chain. The root cause is a missing resource cleanup path: when nvme_add_ctrl() succeeds and admin blk-mq tag set resources are allocated, but subsequent initialization steps fail (such as controller state transitions or connect work scheduling), the code jumps to the fail_ctrl error path which does not invoke nvme_remove_admin_tag_set(). This represents a classic resource leak (CWE-401: Missing Release of Memory after Effective Lifetime). The CVE affects the Linux kernel as identified by CPE cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*, impacting any system using the nvme-fc driver for Fibre Channel NVMe connectivity.
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
3DescriptionNVD
In the Linux kernel, the following vulnerability has been resolved:
nvme-fc: release admin tagset if init fails
nvme_fabrics creates an NVMe/FC controller in following path:
nvmf_dev_write() -> nvmf_create_ctrl() -> nvme_fc_create_ctrl() -> nvme_fc_init_ctrl()
nvme_fc_init_ctrl() allocates the admin blk-mq resources right after nvme_add_ctrl() succeeds. If any of the subsequent steps fail (changing the controller state, scheduling connect work, etc.), we jump to the fail_ctrl path, which tears down the controller references but never frees the admin queue/tag set. The leaked blk-mq allocations match the kmemleak report seen during blktests nvme/fc.
Check ctrl->ctrl.admin_tagset in the fail_ctrl path and call nvme_remove_admin_tag_set() when it is set so that all admin queue allocations are reclaimed whenever controller setup aborts.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
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.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Related Vulnerabilities in Linux Kernel I/O and Data Structure Fixes
View all 4Same weakness CWE-401 – Memory Leak
View allSame technique Information Disclosure
View allVendor StatusVendor
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | vulnerable | 5.10.223-1 | - |
| bullseye (security) | vulnerable | 5.10.251-1 | - |
| bookworm | fixed | 6.1.164-1 | - |
| bookworm (security) | fixed | 6.1.164-1 | - |
| trixie | fixed | 6.12.73-1 | - |
| trixie (security) | fixed | 6.12.74-2 | - |
| forky | fixed | 6.19.6-2 | - |
| sid | fixed | 6.19.8-1 | - |
| (unstable) | fixed | 6.18.10-1 | - |
GitHub PoC
Exploit-DB