Linux Kernel: Race Condition (CVE-2026-80776)
Published Last modified Sources: HKCERT, Ubuntu, BSI, CVE.org, EUVD
What is affected, what to do
In the Linux kernel, the following vulnerability has been resolved: futex: Fix race in futex_pivot_pending() during private hash resize A task performing a custom private hash resize can remain blocked in uninterruptible sleep indefinitely. The hung-task detector reports: INFO: task futex-resizer:314 blocked for more than 10 seconds. task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311 Call Trace: __schedule+0x521/0xf30 schedule+0x22/0xa0 futex_hash_allocate+0x3db/0x490 __do_sys_prctl+0x6f5/0xbd0 do_syscall_64+0xf9/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: hung_task: blocked tasks futex_pivot_pending() allows the resize request to continue when either no replacement hash is pending (hash_new == NULL) or the current hash reference count has reached zero.
Update Linux Kernel to version 6.18.46, Linux Kernel to version 7.1.11, Linux Kernel to version 7.2.
- Affected
- Linux Kernel
lt 6.16..6.18.46 - Linux Kernel
lt 6.19..7.1.11
- Linux Kernel
- Fixed in
- Linux Kernel
6.18.46 - Linux Kernel
7.1.11 - Linux Kernel
7.2
- Linux Kernel
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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, BSI, CVE.org, EUVD
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 5.9
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- 24.14 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- 5.9
- 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: futex: Fix race in futex_pivot_pending() during private hash resize A task performing a custom private hash resize can remain blocked in uninterruptible sleep indefinitely. The hung-task detector reports: INFO: task futex-resizer:314 blocked for more than 10 seconds. task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311 Call Trace: __schedule+0x521/0xf30 schedule+0x22/0xa0 futex_hash_allocate+0x3db/0x490 __do_sys_prctl+0x6f5/0xbd0 do_syscall_64+0xf9/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: hung_task: blocked tasks futex_pivot_pending() allows the resize request to continue when either no replacement hash is pending (hash_new == NULL) or the current hash reference count has reached zero. After the final-reference wake, another futex task can complete the pivot between the two observations: T1 T2 futex_hash_allocate() wait_var_event(mm, ...) futex_pivot_pending(mm) hash_new != NULL futex_hash() futex_ref_get(old) -> false futex_pivot_hash(mm) hash_new = NULL __futex_pivot_hash(mm, new) rcu_assign_pointer(hash, new) fph = rcu_dereference(hash) /* new */ futex_ref_is_dead(fph) -> false schedule() The pivot changes the state from hash_new != NULL with a dead current hash to hash_new == NULL with a live current hash. Because futex_pivot_pending() reads hash_new and hash without serialization, the resize task can observe hash_new in the pre-pivot state and hash in the post-pivot state, causing futex_pivot_pending() to return false even though the pivot has completed. The task then goes to sleep after the wakeup has already been consumed. Serialize state reads in futex_pivot_pending() using futex_mm_phash::lock. This guarantees that futex_pivot_pending() observes hash_new and hash atomically, eliminating the race condition.
Source: HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, Ubuntu Security Notices, BSI WID Portal, BSI CSAF, cvelistv5, ENISA EUVD, CVE.org (MITRE)
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 |
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| Red Hat | OpenShift |
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Vendors and products
Affected operating systems
| Linux | ubuntu | linux | resolute |
| Linux | ubuntu | linux-aws | resolute |
| Linux | ubuntu | linux-aws-7.0 | noble |
| Linux | ubuntu | linux-azure | resolute |
| Linux | ubuntu | linux-azure-fde | resolute |
| Linux | ubuntu | linux-azure-fde-7.0 | noble |
| Linux | ubuntu | linux-gcp | resolute |
| Linux | ubuntu | linux-gcp-7.0 | noble |
| Linux | ubuntu | linux-gke | resolute |
| Linux | ubuntu | linux-hwe-7.0 | noble |
| Linux | ubuntu | linux-ibm | resolute |
| Linux | ubuntu | linux-oem-7.0 | resolute |
| Linux | ubuntu | linux-oracle | resolute |
| Linux | ubuntu | linux-oracle-7.0 | noble |
| Linux | ubuntu | linux-realtime | resolute |
References & sources
- git.kernel.orgstable/c/4a7e941ca29a608c6244cbd028d3599ecaef7207euvd
- git.kernel.orgstable/c/19b4be0717fa83265d66aea836b7022d898422cfeuvd
- git.kernel.orgstable/c/8e7ff730dd96519a333d1570edf1c3fabb6d3629euvd
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).
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: futex: Fix race in futex_pivot_pending() during private hash resize A task performing a custom private hash resize can remain blocked in uninterruptible sleep indefinitely. The hung-task detector reports: INFO: task futex-resizer:314 blocked for more than 10 seconds. task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311 Call Trace: __schedule+0x521/0xf30 schedule+0x22/0xa0 futex_hash_allocate+0x3db/0x490 __do_sys_prctl+0x6f5/0xbd0 do_syscall_64+0xf9/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: hung_task: blocked tasks futex_pivot_pending() allows the resize request to continue when either no replacement hash is pending (hash_new == NULL) or the current hash reference count has reached zero. After the final-reference wake, another futex task can complete the pivot between the two observations: T1 T2 futex_hash_allocate() wait_var_event(mm, ...) futex_pivot_pending(mm) hash_new != NULL futex_hash() futex_ref_get(old) -> false futex_pivot_hash(mm) hash_new = NULL __futex_pivot_hash(mm, new) rcu_assign_pointer(hash, new) fph = rcu_dereference(hash) /* new */ futex_ref_is_dead(fph) -> false schedule() The pivot changes the state from hash_new != NULL with a dead current hash to hash_new == NULL with a live current hash. Because futex_pivot_pending() reads hash_new and hash without serialization, the resize task can observe hash_new in the pre-pivot state and hash in the post-pivot state, causing futex_pivot_pending() to return false even though the pivot has completed. The task then goes to sleep after the wakeup has already been consumed. Serialize state reads in futex_pivot_pending() using futex_mm_phash::lock. This guarantees that futex_pivot_pending() observes hash_new and hash atomically, eliminating the race condition.Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80776.json">CVE-2026-80776</a>Reference added —https://git.kernel.org/stable/c/19b4be0717fa83265d66aea836b7022d898422cfReference added —https://git.kernel.org/stable/c/4a7e941ca29a608c6244cbd028d3599ecaef7207Reference added —https://git.kernel.org/stable/c/8e7ff730dd96519a333d1570edf1c3fabb6d3629Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-80776"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-80776.svg?lang=en" alt="CVE-2026-80776 – NEOSEC Intel" height="20"></a>