MediumCVE-2026-98749

    Linux Kernel: security vulnerability (CVE-2026-98749)

    Published Last modified Sources: Debian LTS, Msrc Update Guide, CVE.org, BSI

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: tty: serial: max3100: shut down timer before freeing port max3100_shutdown() stops the polling timer but returns early during system suspend. If the SPI device is unbound before resume, the serial core does not call max3100_shutdown() again, so max3100_remove() frees the port while the timer remains armed. max3100_timeout() may then access the freed port and re-arm the timer.

    Update Linux Kernel to version 5.10.273, Linux Kernel to version 5.15.224, Linux Kernel to version 6.1.191.

    Affected
    • Linux Kernel lt 2.6.30..5.10.273
    • Linux Kernel lt 5.11..5.15.224
    • Linux Kernel lt 5.16..6.1.191
    • Linux Kernel lt 6.2..6.6.160
    • Linux Kernel lt 6.7..6.12.113
    • Linux Kernel lt 6.13..6.18.56
    • Linux Kernel lt 6.19..7.2.10
    Fixed in
    • Linux Kernel 5.10.273
    • Linux Kernel 5.15.224
    • Linux Kernel 6.1.191
    • Linux Kernel 6.6.160
    • Linux Kernel 6.12.113
    • Linux Kernel 6.18.56
    • Linux Kernel 7.2.10
    • Linux Kernel 7.3

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.7

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    5.7

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: Debian LTS, Msrc Update Guide, CVE.org, BSI

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 8.1

    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
    59.03 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
    5.7 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
    5.7
    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
    8.1
    Low — this CVE sits in the lower 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: tty: serial: max3100: shut down timer before freeing port max3100_shutdown() stops the polling timer but returns early during system suspend. If the SPI device is unbound before resume, the serial core does not call max3100_shutdown() again, so max3100_remove() frees the port while the timer remains armed. max3100_timeout() may then access the freed port and re-arm the timer. Add final timer teardown to max3100_remove() and use timer_shutdown_sync() to prevent a racing callback from re-arming it. Also free the IRQ and destroy the workqueue there before freeing the port. Keep timer_delete_sync() in max3100_shutdown() so that a subsequent open() can re-arm the timer. The workqueue is created before request_irq() and destroyed on both request_irq() failure and normal shutdown. Its presence at remove thus identifies the IRQ left registered when suspend bypasses shutdown. Free the IRQ before destroying the workqueue, in both max3100_shutdown() and max3100_remove(), and cancel the pending work in between. free_irq() waits for a running interrupt handler to finish and no new handler can start afterwards, so a racing handler cannot queue work on a workqueue that is being destroyed; the force_end_work check in max3100_dowork() only narrows that window, as a handler delayed between the check and queue_work() could still run after the teardown has cleared the workqueue pointer. Cancelling the work also keeps destroy_workqueue() from waiting on a queued work item in case remove() ever runs while the freezable workqueue is still frozen, e.g. device removal during the resume window, before workqueues are thawed. This issue was found by an in-house static analysis tool.

    Source: 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 products
    Affected versionsFixed in
    LinuxLinux
    • 5.11 – < 5.15.224
    • 5.16 – < 6.1.191
    • 2.6.30 – < 5.10.273
    • 6.13 – < 6.18.56
    • 6.19 – < 7.2.10
    • 6.7 – < 6.12.113
    • —
    • 6.2 – < 6.6.160
    • 5.15.224
    • 6.1.191
    • 5.10.273
    • 6.18.56
    • 7.2.10
    • 6.12.113
    • 7.3
    • 6.6.160

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinux-6.12bookworm

    References & sources

    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).

    1. Record modifiedLinux

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98749.json">CVE-2026-98749</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/cbb3fcc7cd14396ccc1379c164d96a247331f2e6
      Referenceadded
      —
      https://git.kernel.org/stable/c/d1187a7deac1e90182372a188dfe33ddd2b53cba
      Referenceadded
      —
      https://git.kernel.org/stable/c/fb8cefd66a6055a313c993fa9e8bed9be9b088f6

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    2. Record modifiedLinux

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98749.json">CVE-2026-98749</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/158a07da2da720f2f98b4bea129212c6805d8ee0

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    3. Record modifiedLinux

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98749.json">CVE-2026-98749</a>

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    4. ReceivedLinux

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: tty: serial: max3100: shut down timer before freeing port max3100_shutdown() stops the polling timer but returns early during system suspend. If the SPI device is unbound before resume, the serial core does not call max3100_shutdown() again, so max3100_remove() frees the port while the timer remains armed. max3100_timeout() may then access the freed port and re-arm the timer. Add final timer teardown to max3100_remove() and use timer_shutdown_sync() to prevent a racing callback from re-arming it. Also free the IRQ and destroy the workqueue there before freeing the port. Keep timer_delete_sync() in max3100_shutdown() so that a subsequent open() can re-arm the timer. The workqueue is created before request_irq() and destroyed on both request_irq() failure and normal shutdown. Its presence at remove thus identifies the IRQ left registered when suspend bypasses shutdown. Free the IRQ before destroying the workqueue, in both max3100_shutdown() and max3100_remove(), and cancel the pending work in between. free_irq() waits for a running interrupt handler to finish and no new handler can start afterwards, so a racing handler cannot queue work on a workqueue that is being destroyed; the force_end_work check in max3100_dowork() only narrows that window, as a handler delayed between the check and queue_work() could still run after the teardown has cleared the workqueue pointer. Cancelling the work also keeps destroy_workqueue() from waiting on a queued work item in case remove() ever runs while the freezable workqueue is still frozen, e.g. device removal during the resume window, before workqueues are thawed. This issue was found by an in-house static analysis tool.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98749.json">CVE-2026-98749</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/247b8f680876313586aed4d267bfcceddc2b4901
      Referenceadded
      —
      https://git.kernel.org/stable/c/2c8614981d3e6e000427de0ab2426ab68274d850
      Referenceadded
      —
      https://git.kernel.org/stable/c/db0949bbd06db0a75b4b1076f1e25194be7d956a
      Referenceadded
      —
      https://git.kernel.org/stable/c/fb668620e3b163962dabe1a674725a07aa44ff4a

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

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