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NVD / CVE Program· CNA Linux

CVE-2025-38352: posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()

HighCVSS 7.8 · v3.1KEVWeaponized Fix available

Noroxi assessment

Priority: This week (action score 61/100)

  • CISA has confirmed exploitation in the wild (Sep 4, 2025). Remediation deadline for US federal agencies: Sep 25, 2025.
  • Probability of exploitation in the next 30 days: 1.3% (FIRST EPSS); higher than 72% of all records.
  • 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.
  • Fixed version: Linux Linux 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff, 2f3daa04a9328220de46f0d5c919a6c0073a9f0b, 460188bc042a3f40f72d34b9f7fc6ee66b0b757b; azl3 kernel 6.6.92.2-2 on Azure Linux 3.0 6.6.96.1-1; azl3 kernel 6.6.96.1-1 on Azure Linux 3.0 6.6.96.1-1.

Don’t wait for the next maintenance window. Upgrade to Linux Linux 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff, 2f3daa04a9328220de46f0d5c919a6c0073a9f0b, 460188bc042a3f40f72d34b9f7fc6ee66b0b757b; azl3 kernel 6.6.92.2-2 on Azure Linux 3.0 6.6.96.1-1; azl3 kernel 6.6.96.1-1 on Azure Linux 3.0 6.6.96.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

Published
Jul 22, 2025
Updated
Sep 8, 2026
EPSS
1.3% · 72th percentile

Report tools

JSON

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 US federal agencies: Sep 25, 2025.

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  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
debiandebian linux

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
Affected versions · NVD (9)

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

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-55.32.1.el10_06.12.0-55.32.1.el10_0
AlmaLinux:10kernel-docbefore 6.12.0-55.32.1.el10_06.12.0-55.32.1.el10_0
AlmaLinux:8bpftoolbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.74.1.el8_104.18.0-553.74.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.74.1.rt7.415.el8_104.18.0-553.74.1.rt7.415.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-38350Jul 19, 2025 · net/sched: Always pass notifications when child class becomes empty
    31Monitor
  • ← EarlierCVE-2025-38351Jul 19, 2025 · KVM: x86/hyper-v: Skip non-canonical addresses during PV TLB flush
    22Monitor
  • Later →CVE-2025-38354Jul 25, 2025 · drm/msm/gpu: Fix crash when throttling GPU immediately during boot
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2c72fe18cc5f9f1750f5bc148cf1c94c29e106ffVendor (CNA)
Linux Linux2f3daa04a9328220de46f0d5c919a6c0073a9f0bVendor (CNA)
Linux Linux460188bc042a3f40f72d34b9f7fc6ee66b0b757bVendor (CNA)
Linux Linux764a7a5dfda23f69919441f2eac2a83e7db6e5bbVendor (CNA)
Linux Linux78a4b8e3795b31dae58762bc091bb0f4f74a2200Vendor (CNA)
Linux Linuxc076635b3a42771ace7d276de8dc3bc76ee2ba1bVendor (CNA)
Linux Linuxc29d5318708e67ac13c1b6fc1007d179fb65b4d7Vendor (CNA)
Linux Linuxf90fff1e152dedf52b932240ebbd670d83330ecaVendor (CNA)
azl3 kernel 6.6.92.2-2 on Azure Linux 3.06.6.96.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.96.1-1 on Azure Linux 3.06.6.96.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.74.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.147-1 · Debian:12Package registry (OSV)
red hat:bpftool0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-553.74.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage 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.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHub6 repositories2025-12-21 → 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.

  1. Published
  2. CISA KEV+44 d
  3. First PoC+152 d
  4. TodayNov 14, 2026+480 d

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 vlans
    39Monitor
  • CVE-2026-64034362 days apartnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
    37Monitor
  • CVE-2026-63937362 days apartKVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer
    35Monitor
  • CVE-2026-63867362 days apartmptcp: close TOCTOU race while computing rcv_wnd
    32Monitor
  • CVE-2026-31678277 days apartopenvswitch: defer tunnel netdev_put to RCU release
    31Monitor
  • CVE-2026-43433290 days apartrust_binder: avoid reading the written value in offsets array
    31Monitor

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · public bounty program.

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 Condition

CVSS 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.

ATT&CK techniques

—

References

Show all references (10 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records