Exploited CVEs / Linux / CVE-2025-38352

CVE-2025-38352

Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2025-09-25 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

Risk summary

HighCISA KEV
7.8
CVSS base
1.3%
EPSS exploit probability
High
Severity
2025-09-04
Added to KEV
2025-09-25 (past due)
CISA due date

Actively exploited Linux Kernel vulnerability, High severity, CVSS 7.8. Added to the CISA KEV catalog 2025-09-04.

Senserva AI read on CVE-2025-38352CISA required actionOfficial fix for CVE-2025-38352Admin questions

Senserva AI Opinion for CVE-2025-38352

This is a Linux kernel race condition in posix-cpu-timers where handle_posix_cpu_timers() and posix_cpu_timer_del() can collide, affecting azl3 kernel builds 6.6.96.1-1 and 6.6.92.2-2 on Azure Linux 3.0. Despite a low 1% EPSS score, CISA added it to the Known Exploited Vulnerabilities catalog on 2025-09-04, so it is confirmed exploited in the wild. Timer race conditions like this are typically leveraged for local privilege escalation, meaning any user with local access to these hosts is a concern.

Do this: Patch the azl3 kernel on all Azure Linux 3.0 hosts running 6.6.96.1-1 or 6.6.92.2-2 to a fixed build and reboot to load it.

AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2025-38352

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Patch now
Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.
No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.
Do this now: Federal remediation deadline 2025-09-25; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 15, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2025-38352

Published
2025-08-07
Last revised
2026-02-18
Changes tracked
1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one
What changed, and when

The strongest signal is the CVSS Severity increase from 7.4 to 7.8 on 2026-08-04, raising the impact rating. Exploitation likelihood stayed low and flat, with EPSS opening at 1.4% on 2026-07-17, easing to 1.3% by 2026-07-30, and holding at 1.3% on 2026-08-11. Prioritize based on the higher Severity while exploit pressure remains minimal.

0%25%50%75%100%CISA KEVCISA KEV on 2025-09-042026-07-17: EPSS 1.4%2026-07-30: EPSS 1.3%2026-08-04: EPSS 1.3%2026-08-11: EPSS 1.3%EPSS 1.3%2025-09-042026-08-11

Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.

  • 2025-09-04 added to the CISA KEV catalog by CISA
  • 2026-07-17 EPSS first scored at 1.4%
  • 2026-07-30 EPSS 1.4% to 1.3%
  • 2026-08-04 CVSS 7.4 to 7.8
  • 2026-08-11 EPSS 1.3% to 1.3%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2025-09-25 (past due).

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Official fix for CVE-2025-38352

Check the vendor's security advisory channel for the patched Kernel versions and workarounds.

CISA KEV entry

Common questions about CVE-2025-38352

Is CVE-2025-38352 actively exploited?

Yes. CVE-2025-38352 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2025-09-04, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 1.3%.

What is the CISA deadline and required action for CVE-2025-38352?

CISA set the federal (BOD 22-01) remediation due date at 2025-09-25, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

What fixes CVE-2025-38352?

Check the vendor's security advisory for the patched Kernel versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2025-38352?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2025-38352's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

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Authoritative references
CVE recordNVD detailCISA KEV catalogFIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
Provided as is, without warranty; verify against the vendor advisory before acting. Data notice and terms.