Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2025-38352

Linux

Linux · affected before 78a4b8e3795b31dae58762bc091bb0f4f74a2200

Watch CVE-2025-38352 Browse KEV feed
Severity
CVSS 7.8 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
1.3%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2025-38352 is a vulnerability affecting Linux. 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...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Linux affected before 78a4b8e3795b31dae58762bc091bb0f4f74a2200.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Linux

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.

Linux Affected
Linux
Before 78a4b8e3795b31dae58762bc091bb0f4f74a2200 Before c076635b3a42771ace7d276de8dc3bc76ee2ba1b Before 2f3daa04a9328220de46f0d5c919a6c0073a9f0b Before 764a7a5dfda23f69919441f2eac2a83e7db6e5bb Before 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff Before c29d5318708e67ac13c1b6fc1007d179fb65b4d7 Before 460188bc042a3f40f72d34b9f7fc6ee66b0b757b Before f90fff1e152dedf52b932240ebbd670d83330eca 2.6.36
Linux Unaffected
Linux
Before 2.6.36 Through 5.4.* Through 5.10.* Through 5.15.* Through 6.1.* Through 6.6.* Through 6.12.* Through 6.15.* Through *
Published
22 Jul 2025
Exploitation Reported
01 Jun 2026
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None

Tags

cisa linux

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 01 Jun 2026

A trusted third party reported exploitation.

Proof of concept available

CVE

Recorded 08 Sep 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2026-06-01 10:40 UTC
CISA 2026-06-02 14:06 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.8 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

1.3%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Time-of-check Time-of-use (TOCTOU) Race Condition CWE-367

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

CVE Record exploit — github.com

cve · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 15:50 UTC

    Public PoC available

    Public proof-of-concept code published

  2. 14:06 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  3. 10:40 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  4. 08:04 UTC

    CVE published

    Vulnerability disclosed publicly

  5. 04:51 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2025-38352

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2025-38352",
  "confidence": "Confirmed",
  "cvss_score": 7.8,
  "cvss_estimated": false,
  "epss_score": 0.01289,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}