posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()
In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del() If an exiting non-autoreaping task has already passed exit_notify() and calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent or debugger right after unlock_task_sighand(). If a concurrent posix_cpu_timer_del() runs at that moment, it won't be able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or lock_task_sighand() will fail. Add the tsk->exit_state check into run_posix_cpu_timers() to fix this. This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because exit_task_work() is called before exit_notify(). But the check still makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail anyway in this case.
- BDU:2025-10870
- ALSA-2025:15471
- ALSA-2025:15472
- ALSA-2025:15661
- ALSA-2025:15662
- RHSA-2025:15471
- RHSA-2025:15472
- RHSA-2025:15646
- RHSA-2025:15647
- RHSA-2025:15648
- RHSA-2025:15649
- RHSA-2025:15656
- RHSA-2025:15657
- RHSA-2025:15658
- RHSA-2025:15660
- RHSA-2025:15661
- RHSA-2025:15662
- RHSA-2025:15668
- RHSA-2025:15669
- RHSA-2025:15670
- Published
- Jul 22, 2025
- Updated
- Sep 8, 2026
- EPSS
- 1.3% · 69th percentile
- CWE
- CWE-367
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Report tools
Action score
61
This week
Don’t wait for the next maintenance window.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 0 / 30 · 1.3%
CISA SSVC decision
- Exploitation
- active
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Sep 4, 2025. That signals real attacks, not theory.
Remediation deadline for government agencies: Sep 25, 2025.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux11.0
- linux linux kernel5.5 and later · before 5.10.239
- linux linux kernel5.11 and later · before 5.15.186
- linux linux kernel5.16 and later · before 6.1.142
- linux linux kernel2.6.36 and later · before 5.4.295
- linux linux kernel6.7 and later · before 6.12.34
- linux linux kernel6.13 and later · before 6.15.3
- linux linux kernel6.2 and later · before 6.6.94
- linux linux kernel6.16
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 2.6.36affected
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before 78a4b8e3795b31dae58762bc091bb0f4f74a2200affected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before c076635b3a42771ace7d276de8dc3bc76ee2ba1baffected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before 2f3daa04a9328220de46f0d5c919a6c0073a9f0baffected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before 764a7a5dfda23f69919441f2eac2a83e7db6e5bbaffected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ffaffected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before c29d5318708e67ac13c1b6fc1007d179fb65b4d7affected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before 460188bc042a3f40f72d34b9f7fc6ee66b0b757baffected · git
- 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and later · before f90fff1e152dedf52b932240ebbd670d83330ecaaffected · git
- before 2.6.36not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | kernel-abi-stablelists | before 6.12.0-55.32.1.el10_0 | 6.12.0-55.32.1.el10_0 |
| AlmaLinux:10 | kernel-doc | before 6.12.0-55.32.1.el10_0 | 6.12.0-55.32.1.el10_0 |
| AlmaLinux:8 | bpftool | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-abi-stablelists | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-core | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-cross-headers | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-debug | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-debug-core | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-debug-devel | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules-extra | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-devel | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-doc | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-headers | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-modules | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-modules-extra | before 4.18.0-553.74.1.el8_10 | 4.18.0-553.74.1.el8_10 |
| AlmaLinux:8 | kernel-rt | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
| AlmaLinux:8 | kernel-rt-core | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
| AlmaLinux:8 | kernel-rt-debug | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-core | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-devel | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules-extra | before 4.18.0-553.74.1.rt7.415.el8_10 | 4.18.0-553.74.1.rt7.415.el8_10 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff | Vendor (CNA) |
| Linux Linux | 2f3daa04a9328220de46f0d5c919a6c0073a9f0b | Vendor (CNA) |
| Linux Linux | 460188bc042a3f40f72d34b9f7fc6ee66b0b757b | Vendor (CNA) |
| Linux Linux | 764a7a5dfda23f69919441f2eac2a83e7db6e5bb | Vendor (CNA) |
| Linux Linux | 78a4b8e3795b31dae58762bc091bb0f4f74a2200 | Vendor (CNA) |
| Linux Linux | c076635b3a42771ace7d276de8dc3bc76ee2ba1b | Vendor (CNA) |
| Linux Linux | c29d5318708e67ac13c1b6fc1007d179fb65b4d7 | Vendor (CNA) |
| Linux Linux | f90fff1e152dedf52b932240ebbd670d83330eca | Vendor (CNA) |
| azl3 kernel 6.6.92.2-2 on Azure Linux 3.0 | 6.6.96.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 kernel 6.6.96.1-1 on Azure Linux 3.0 | 6.6.96.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| AlmaLinux:bpftool | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-abi-stablelists | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-core | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-cross-headers | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-debug | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-debug-core | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-debug-devel | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-debug-modules | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-debug-modules-extra | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-devel | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| AlmaLinux:kernel-doc | 4.18.0-553.74.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| Debian:linux | 6.1.147-1 · Debian:12 | Package registry (OSV) |
| Red Hat:bpftool | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| Red Hat:bpftool-debuginfo | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| Red Hat:kernel | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| Red Hat:kernel-abi-stablelists | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| Red Hat:kernel-core | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| Red Hat:kernel-debug | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| Red Hat:kernel-debug-core | 0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
+18
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Proof-of-concept repository on GitHub ×6
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:117 | 2025-12-21 |
| Proof-of-concept repository on GitHub | stars:312 | 2026-01-03 |
| Proof-of-concept repository on GitHub | stars:0 | 2026-01-08 |
| Proof-of-concept repository on GitHub | stars:2 | 2026-02-24 |
| Proof-of-concept repository on GitHub | stars:17 | 2026-05-30 |
| Proof-of-concept repository on GitHub | stars:0 | 2026-09-13 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- CISA KEV+44 d
- First PoC+152 d
- TodaySep 29, 2026+435 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-64091362 days apartbatman-adv: tt: fix TOCTOU race for reported vlans39Monitor
- CVE-2026-31678277 days apartopenvswitch: defer tunnel netdev_put to RCU release31Monitor
- CVE-2026-43433290 days apartrust_binder: avoid reading the written value in offsets array31Monitor
- CVE-2026-53145338 days apartdrm/gem: Try to fix change_handle ioctl, attempt 431Monitor
- CVE-2026-53250338 days apartxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()31Monitor
- CVE-2026-64112362 days apartrbd: eliminate a race in lock_dwork draining on unmap31Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race ConditionCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff
- git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b
- git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b
- git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb
- git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200
- git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b
- git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7
- git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca
- lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-38352
Vendor advisories and official records. Exploit/PoC links are deliberately left out.