Linux Kernel: Race Condition (CVE-2026-98580)
Published Last modified Sources: Ubuntu, Debian LTS, Msrc Update Guide, CVE.org, BSI
What is affected, what to do
Update Linux Kernel to version 5.10.271, Linux Kernel to version 5.15.222, Linux Kernel to version 6.1.189.
- Affected
- Linux Kernel
lt 3.7..5.10.271 - Linux Kernel
lt 5.11..5.15.222 - Linux Kernel
lt 5.16..6.1.189 - Linux Kernel
lt 6.2..6.6.158 - Linux Kernel
lt 6.7..6.12.112 - Linux Kernel
lt 6.13..6.18.55 - Linux Kernel
lt 6.19..7.2.9
- Linux Kernel
- Fixed in
- Linux Kernel
5.10.271 - Linux Kernel
5.15.222 - Linux Kernel
6.1.189 - Linux Kernel
6.6.158 - Linux Kernel
6.12.112 - Linux Kernel
6.18.55 - Linux Kernel
7.2.9 - Linux Kernel
7.3
- Linux Kernel
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Metrics
5.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
5.8
CVSS v3
Severity Medium on the scale from 0 to 10.
Source: Ubuntu, Debian LTS, Msrc Update Guide, CVE.org, BSI
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 12.1
Show all metrics
- Severity
- Medium
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- 60.17 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- 5.8 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- 5.8
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- 0.2 %
- 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- 12.1
- Elevated — this CVE ranks above at least 10% of all CVEs scored today.
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- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
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
In the Linux kernel, the following vulnerability has been resolved:
nfc: llcp: Fix race condition in accept_queue lifecycle
In nfc_llcp_socket_release(), sockets and listener accept queues are walked under the local sockets rwlock and bh_lock_sock(). However, bh_lock_sock() does not synchronise against process-context lock_sock() held by nfc_llcp_accept_dequeue() during accept(). Because socket_release() does not check sock_owned_by_user(), both paths can concurrently unlink and release the same child socket, resulting in use-after-free or a NULL pointer dereference of child->parent in nfc_llcp_accept_unlink().
Fix this synchronisation race by having nfc_llcp_socket_release() use process-context lock_sock() instead of bh_lock_sock():
-
Pop sockets from the local sockets list under the write lock using nfc_llcp_sock_list_pop() so lock_sock() can be acquired without holding the rwlock.
-
Because lock_sock() can sleep, defer the final release of the nfc_llcp_local structure to a workqueue (release_work). This avoids a sleeping-in-atomic bug when the last local reference is dropped from softirq context. Additionally, hold a single device reference on local from registration until final destruction.
-
In nfc_llcp_local_get(), use kref_get_unless_zero() to prevent resurrecting a local object whose teardown has been scheduled.
-
In llcp_sock_accept(), verify that the listener socket state is still LLCP_LISTEN after waking from schedule_timeout() to prevent hangs if the listener is closed concurrently.
-
When unlinking unaccepted child sockets during listener release, unlink them from local->sockets, call sock_orphan(), and drop their initial sk_alloc creation reference via sock_put().
-
Make nfc_llcp_accept_unlink() idempotent by guarding parent access with a NULL check.
Source: Ubuntu Security Notices, Debian LTS Advisories, Microsoft Security Update Guide, cvelistv5, NVD (NIST), 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 | ubuntu | linux | jammy |
| Linux | ubuntu | linux | resolute |
| Linux | debian | linux-6.12 | bookworm |
| Linux | ubuntu | linux-aws | jammy |
| Linux | ubuntu | linux-aws | resolute |
| Linux | ubuntu | linux-aws-5.15 | focal |
| Linux | ubuntu | linux-aws-fips | jammy |
| Linux | ubuntu | linux-azure | jammy |
| Linux | ubuntu | linux-azure-5.15 | focal |
| Linux | ubuntu | linux-azure-fde-5.15 | focal |
| Linux | ubuntu | linux-azure-fips | jammy |
| Linux | ubuntu | linux-fips | jammy |
| Linux | ubuntu | linux-gcp | jammy |
| Linux | ubuntu | linux-gcp | resolute |
| Linux | ubuntu | linux-gcp-5.15 | focal |
| Linux | ubuntu | linux-gcp-fips | jammy |
| Linux | ubuntu | linux-gke | jammy |
| Linux | ubuntu | linux-gkeop | jammy |
| Linux | ubuntu | linux-hwe-5.15 | focal |
| Linux | ubuntu | linux-hwe-7.0 | noble |
| Linux | ubuntu | linux-ibm | jammy |
| Linux | ubuntu | linux-ibm | resolute |
| Linux | ubuntu | linux-ibm-5.15 | focal |
| Linux | ubuntu | linux-intel-iot-realtime | jammy |
References & sources
- git.kernel.orgstable/c/41256821762a7114906b178826d17098e2fa5992
- git.kernel.orgstable/c/53867f6acb1af7f12d6485fa8a2819318f89083b
- git.kernel.orgstable/c/54adcabb0f1deef1bdae5fc64779ed6d442721c9
- git.kernel.orgstable/c/7c938aad5108382c6ad7453c4b5ee8ae3f3252ed
- git.kernel.orgstable/c/c3eef2f988a3db9690369d7cef9a3344dd9788d3
- git.kernel.orgstable/c/d2093a0981138876212bc5f473bdbfba0786e064
- git.kernel.orgstable/c/d5e1c92d09caed19f2988739695ce611a86ba6f8
- git.kernel.orgstable/c/da8a07757383614a8380a0f7dd54749d2687b82e
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
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/2026/98xxx/CVE-2026-98580.json">CVE-2026-98580</a>Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
ReceivedLinux
Description added or changed
New references:- https://git.kernel.org/stable/c/41256821762a7114906b178826d17098e2fa5992
- https://git.kernel.org/stable/c/53867f6acb1af7f12d6485fa8a2819318f89083b
- https://git.kernel.org/stable/c/54adcabb0f1deef1bdae5fc64779ed6d442721c9
- https://git.kernel.org/stable/c/7c938aad5108382c6ad7453c4b5ee8ae3f3252ed
and 4 more references
Show 10 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: nfc: llcp: Fix race condition in accept_queue lifecycle In nfc_llcp_socket_release(), sockets and listener accept queues are walked under the local sockets rwlock and bh_lock_sock(). However, bh_lock_sock() does not synchronise against process-context lock_sock() held by nfc_llcp_accept_dequeue() during accept(). Because socket_release() does not check sock_owned_by_user(), both paths can concurrently unlink and release the same child socket, resulting in use-after-free or a NULL pointer dereference of child->parent in nfc_llcp_accept_unlink(). Fix this synchronisation race by having nfc_llcp_socket_release() use process-context lock_sock() instead of bh_lock_sock(): 1. Pop sockets from the local sockets list under the write lock using nfc_llcp_sock_list_pop() so lock_sock() can be acquired without holding the rwlock. 2. Because lock_sock() can sleep, defer the final release of the nfc_llcp_local structure to a workqueue (release_work). This avoids a sleeping-in-atomic bug when the last local reference is dropped from softirq context. Additionally, hold a single device reference on local from registration until final destruction. 3. In nfc_llcp_local_get(), use kref_get_unless_zero() to prevent resurrecting a local object whose teardown has been scheduled. 4. In llcp_sock_accept(), verify that the listener socket state is still LLCP_LISTEN after waking from schedule_timeout() to prevent hangs if the listener is closed concurrently. 5. When unlinking unaccepted child sockets during listener release, unlink them from local->sockets, call sock_orphan(), and drop their initial sk_alloc creation reference via sock_put(). 6. Make nfc_llcp_accept_unlink() idempotent by guarding parent access with a NULL check.Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98580.json">CVE-2026-98580</a>Reference added —https://git.kernel.org/stable/c/41256821762a7114906b178826d17098e2fa5992Reference added —https://git.kernel.org/stable/c/53867f6acb1af7f12d6485fa8a2819318f89083bReference added —https://git.kernel.org/stable/c/54adcabb0f1deef1bdae5fc64779ed6d442721c9Reference added —https://git.kernel.org/stable/c/7c938aad5108382c6ad7453c4b5ee8ae3f3252edReference added —https://git.kernel.org/stable/c/c3eef2f988a3db9690369d7cef9a3344dd9788d3Reference added —https://git.kernel.org/stable/c/d2093a0981138876212bc5f473bdbfba0786e064Reference added —https://git.kernel.org/stable/c/d5e1c92d09caed19f2988739695ce611a86ba6f8Reference added —https://git.kernel.org/stable/c/da8a07757383614a8380a0f7dd54749d2687b82eSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-98580"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-98580.svg?lang=en" alt="CVE-2026-98580 – NEOSEC Intel" height="20"></a>