Not ratedCVE-2026-80775

    Linux Kernel: Use-After-Free (CVE-2026-80775)

    Published Last modified Sources: HKCERT, Ubuntu, Red Hat, pwn.watch, BSI, CVE.org, EUVD

    Share

    What is affected, what to do

    A flaw was found in the Linux kernel. A race condition exists in the `futex_hash_allocate()` function, specifically during the initial allocation of `mm->futex.phash.ref`.

    Update Linux Kernel to version 6.18.47, Linux Kernel to version 7.1.11, Linux Kernel to version 7.2.1.

    Affected
    • Linux Kernel lt 6.17..6.18.47
    • Linux Kernel lt 6.19..7.1.11
    • Linux Kernel lt 7.2..7.2.1
    Fixed in
    • Linux Kernel 6.18.47
    • Linux Kernel 7.1.11
    • Linux Kernel 7.2.1
    • Linux Kernel 7.3

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

    Metrics

    —

    XIEM Effective CVSS

    No value is available for this vulnerability.

    0.0

    CVSS v3

    Severity Not rated on the scale from 0 to 10.

    Source: HKCERT, Ubuntu, Red Hat, pwn.watch, BSI, CVE.org, EUVD

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 8.2

    Show all metrics
    Severity
    Not rated
    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
    24.60 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
    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
    0.0
    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
    8.2
    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

    A flaw was found in the Linux kernel. A race condition exists in the `futex_hash_allocate()` function, specifically during the initial allocation of `mm->futex.phash.ref`. This vulnerability can be triggered in scenarios involving nested `vfork` calls, where a parent and grandchild process might concurrently attempt to set futex hash slots. This race can lead to a use-after-free condition, allowing a task to write into freed memory, which results in memory corruption.

    Source: HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, Ubuntu Security Notices, redhat_csaf, pwn.watch, BSI WID Portal, BSI CSAF, NVD (NIST), CVE.org (MITRE), ENISA EUVD, cvelistv5

    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
    • 7.2 – < 7.2.1
    • 6.17 – < 6.18.47
    • —
    • 6.19 – < 7.1.11
    • 7.2.1
    • 6.18.47
    • 7.3
    • 7.1.11
    Red HatOpenShift
    • Container Platform
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxubuntulinuxresolute
    Linuxubuntulinux-awsresolute
    Linuxubuntulinux-aws-7.0noble
    Linuxubuntulinux-azureresolute
    Linuxubuntulinux-azure-fderesolute
    Linuxubuntulinux-azure-fde-7.0noble
    Linuxubuntulinux-gcpresolute
    Linuxubuntulinux-gcp-7.0noble
    Linuxubuntulinux-gkeresolute
    Linuxubuntulinux-hwe-7.0noble
    Linuxubuntulinux-ibmresolute
    Linuxubuntulinux-oem-7.0resolute
    Linuxubuntulinux-oracleresolute
    Linuxubuntulinux-oracle-7.0noble
    Linuxubuntulinux-realtimeresolute

    References & sources

    • git.kernel.orgstable/c/86d12b34bafc9a4c271a9edefea88855a934d6e5euvd
    • git.kernel.orgstable/c/ff252ed45c8263525f2f54d81c5fa6d547fba344euvd
    • git.kernel.orgstable/c/c4b4972d8edcdf50b6518f55119e129d2f668a10euvd
    • git.kernel.orgstable/c/bde0238083647381d4747355c5a19115a3422b96euvd
    • pwn.watchpwn.watch: Infinity Core: six Linux kernel core bugs with public root exploits and container escapes (CVE-2026-98260 and others)pwn-watch
    • openwall.comoss-security: Infinity Core: Linux Kernel Core LPEspwn-watch
    • github.comInfinity Core: Linux Kernel Core LPEs (write-ups and PoCs)pwn-watch
    • CVE.org (MITRE)CVE-2026-98260: exec: Cleanup POSIX timers right after de_thread()pwn-watch
    • git.kernel.orgLinux mainline fix for CVE-2026-98260 (acb03d388181)pwn-watch
    • linuxsecurity.comFive Linux Kernel Exploits Enable Root and Container Escapepwn-watch

    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

      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/2026/80xxx/CVE-2026-80775.json">CVE-2026-80775</a>

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

    2. 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: futex: Fix race on the initial mm->futex.phash.ref allocation futex_hash_allocate() allocates mm->futex.phash.ref without any locking. Commit d9b05321e21e ("futex: Move futex_hash_free() back to __mmput()") moved the allocation here and assumed that the process has just a single thread at this point. Commit ee9dce44362b ("futex: Drop CLONE_THREAD requirement for private default hash alloc") widened need_futex_hash_allocate_default() to cover any CLONE_VM clone, but left out vfork because the parent is suspended and cannot race. That no longer holds once vfork is nested. If a vfork child calls vfork again and is then killed with SIGKILL, the parent is released from its vfork wait and runs concurrently with the grandchild in the same mm. Neither of them went through futex_hash_allocate_default(). When both call prctl(PR_FUTEX_HASH, PR_FUTEX_HASH_SET_SLOTS) at the same time, each one sees mm->futex.phash.ref as NULL and stores its own percpu counter. Only the last store survives. The counter stored first is no longer reachable from the mm, so the references on it are not seen by __futex_ref_atomic_end(). A private hash that still has references is then considered dead and freed, and a task that still holds one of its buckets writes into freed memory in futex_q_lock(). Store the counter once with cmpxchg() and let the loser free_percpu() its own. The initial reference has to be taken before the store, otherwise another task can install a private hash while the counter is still 0.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80775.json">CVE-2026-80775</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/86d12b34bafc9a4c271a9edefea88855a934d6e5
      Referenceadded
      —
      https://git.kernel.org/stable/c/bde0238083647381d4747355c5a19115a3422b96
      Referenceadded
      —
      https://git.kernel.org/stable/c/c4b4972d8edcdf50b6518f55119e129d2f668a10
      Referenceadded
      —
      https://git.kernel.org/stable/c/ff252ed45c8263525f2f54d81c5fa6d547fba344

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

    Embed badge

    Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.

    Badge preview for CVE-2026-80775
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-80775"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-80775.svg?lang=en" alt="CVE-2026-80775 – NEOSEC Intel" height="20"></a>