Linux Kernel: security vulnerability (CVE-2026-89972)
Published Last modified Sources: Debian LTS, Debian, Msrc Update Guide, CVE.org, Red Hat, BSI
What is affected, what to do
A flaw was found in the NVMe (Non-Volatile Memory Express) driver of the Linux kernel. The nvme_alloc_ns() function's error handling path fails to wait for all SRCU (Sleepable Read-Copy Update) readers to complete before freeing a namespace structure.
Update Linux Kernel to version 6.6.160, Linux Kernel to version 6.12.112, Linux Kernel to version 6.18.51.
- Affected
- Linux Kernel
lt 4.15..6.6.160 - Linux Kernel
lt 6.7..6.12.112 - Linux Kernel
lt 6.13..6.18.51 - Linux Kernel
lt 6.19..7.2.5
- Linux Kernel
- Fixed in
- Linux Kernel
6.6.160 - Linux Kernel
6.12.112 - Linux Kernel
6.18.51 - Linux Kernel
7.2.5 - Linux Kernel
7.3
- Linux Kernel
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Metrics
9.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
9.8
CVSS v3
Severity Critical on the scale from 0 to 10.
Source: Debian LTS, Debian, Msrc Update Guide, CVE.org, Red Hat, BSI
0.6 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 50.1
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 96.79 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.8
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.6 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 50.1
- High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
A flaw was found in the NVMe (Non-Volatile Memory Express) driver of the Linux kernel. The nvme_alloc_ns() function's error handling path fails to wait for all SRCU (Sleepable Read-Copy Update) readers to complete before freeing a namespace structure. This oversight allows a concurrent reader to access a freed memory region, leading to a use-after-free vulnerability. A local attacker could potentially exploit this to cause a system crash or achieve arbitrary code execution.
Source: Debian LTS Advisories, Debian Security Advisories, Microsoft Security Update Guide, NVD (NIST), redhat_csaf, cvelistv5, BSI WID Portal, BSI CSAF
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Linux | Linux |
|
|
Vendors and products
Affected operating systems
| Linux | debian | linux | trixie |
| Linux | debian | linux-6.12 | bookworm |
References & sources
- git.kernel.orgstable/c/d663944dbad81bb0e3635d7090db4713e6300858
- git.kernel.orgstable/c/76023560d60f10b4f808941163aa2975f1631683
- git.kernel.orgstable/c/ef248d5de4469fb6bbaf8dbe0c4c47800080d648
- git.kernel.orgstable/c/0d4735418512ef825176726eaaa8bd6a35f6b46d
- git.kernel.orgstable/c/3868476cd39161f18720582df17a1b621e805b5d
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedLinux
Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89972.json">CVE-2026-89972</a>Reference added —https://git.kernel.org/stable/c/3868476cd39161f18720582df17a1b621e805b5dSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record modifiedLinux
1 individual change: Affected versions (publisher)
Show the original change
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89972.json">CVE-2026-89972</a>Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record modifiedLinux
Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89972.json">CVE-2026-89972</a>Reference added —https://git.kernel.org/stable/c/0d4735418512ef825176726eaaa8bd6a35f6b46dSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record modifiedLinux
CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show the original change
Individual changes of this event as published by NVD Type Action Before After CVSS added —AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
ReceivedLinux
Description added or changed
Show 5 original changes
Individual changes of this event as published by NVD Type Action Before After Description added —In the Linux kernel, the following vulnerability has been resolved: nvme: add missing SRCU grace period in error path nvme_alloc_ns() error path at out_unlink_ns removes ns from the namespace head siblings list with list_del_rcu(&ns->siblings) but does not wait for SRCU readers before freeing the namespace struct. Multipath code iterates the head->list under srcu_read_lock() in nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent reader can still hold a reference to ns when kfree(ns) runs. The normal removal path in nvme_ns_remove() correctly calls synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for in-progress readers. Add the same grace period in the error path.Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89972.json">CVE-2026-89972</a>Reference added —https://git.kernel.org/stable/c/76023560d60f10b4f808941163aa2975f1631683Reference added —https://git.kernel.org/stable/c/d663944dbad81bb0e3635d7090db4713e6300858Reference added —https://git.kernel.org/stable/c/ef248d5de4469fb6bbaf8dbe0c4c47800080d648Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-89972"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-89972.svg?lang=en" alt="CVE-2026-89972 – NEOSEC Intel" height="20"></a>