⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Not verified · CVSS 0.0 ⚠ ACTIVELY EXPLOITED — CISA KEV

How to Fix CVE-2025-38352: Security Vulnerability in Linux Linux

By Sai Kiran Pandrala

⚡ At a glance
SeverityCVSS 0.0
Actively exploited?Yes, listed in CISA KEV (added 2025-09-04, federal due date 2025-09-25)
AffectedLinux: 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version 78a4b8e3795b31dae58762bc091bb0f4f74a2200, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version c076635b3a42771ace7d276de8dc3bc76ee2ba1b, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version 2f3daa04a9328220de46f0d5c919a6c0073a9f0b, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version 764a7a5dfda23f69919441f2eac2a83e7db6e5bb, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version c29d5318708e67ac13c1b6fc1007d179fb65b4d7, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version 460188bc042a3f40f72d34b9f7fc6ee66b0b757b, 0bdd2ed4138ec04e09b4f8165981efc99e439f55 < version f90fff1e152dedf52b932240ebbd670d83330eca; Linux: 2.6.36
Fixed inLinux: 78a4b8e3795b31dae58762bc091bb0f4f74a2200, c076635b3a42771ace7d276de8dc3bc76ee2ba1b, 2f3daa04a9328220de46f0d5c919a6c0073a9f0b, 764a7a5dfda23f69919441f2eac2a83e7db6e5bb, 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff, c29d5318708e67ac13c1b6fc1007d179fb65b4d7, 460188bc042a3f40f72d34b9f7fc6ee66b0b757b, f90fff1e152dedf52b932240ebbd670d83330eca
Type (CWE)Not verified, see official advisory

What is CVE-2025-38352?

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

A successful exploit gives the attacker the impact described in the vendor advisory. The fix is to install the patched build from Linux listed in the table above and confirm the running version after the upgrade.

Am I affected?

Check your installed version of Linux Linux against the Affected row above. If your build sits within any of those ranges, treat the system as vulnerable until patched.

If you do not have the version handy, pull it the same way you usually would for Linux: the management console's About page, the CLI's version command, or the package manager record for the installed binary. The vendor advisory linked in the references section is the authoritative source.

How to fix CVE-2025-38352

  1. Read the vendor advisory at https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200 for the build matrix that matches your installation.
  2. Identify the patched build for your major version: Linux: 78a4b8e3795b31dae58762bc091bb0f4f74a2200, c076635b3a42771ace7d276de8dc3bc76ee2ba1b, 2f3daa04a9328220de46f0d5c919a6c0073a9f0b, 764a7a5dfda23f69919441f2eac2a83e7db6e5bb, 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff, c29d5318708e67ac13c1b6fc1007d179fb65b4d7, 460188bc042a3f40f72d34b9f7fc6ee66b0b757b, f90fff1e152dedf52b932240ebbd670d83330eca.
  3. Back up configuration before upgrading (export running config, snapshot the VM, or take a database dump as appropriate for your platform).
  4. Apply the patched build using the vendor's documented upgrade path (in-place upgrade, package update, or replacement image).
  5. Restart the service so the new code is loaded; verify the running version reports the patched build number.

Patch via your OS package manager


# Patched version is 5.4.295 (from the vendor advisory).
# Debian / Ubuntu
sudo apt update
sudo apt install --only-upgrade linux-image-generic=5.4.295

# RHEL / Rocky / AlmaLinux / Fedora
sudo dnf upgrade linux-image-generic

# openSUSE
sudo zypper update linux-image-generic

# Verify the running version matches the fixed version
dpkg -s linux-image-generic 2>/dev/null | grep -i version || rpm -q linux-image-generic 2>/dev/null


# Windows: pull the cumulative update that ships this fix.
Install-Module PSWindowsUpdate -Force -SkipPublisherCheck
Get-WindowsUpdate -AcceptAll -Install -AutoReboot

Verify the fix landed


# 1. Confirm the running version matches the fixed-in version from the advisory:
#    https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200
#    Use the platform-specific version probe above.

# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag CVE-2025-38352 on the patched target.

# 3. Inspect recent service / kernel logs for crash loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

If you can't patch immediately

Check the vendor advisory's "Workarounds" section. If the advisory lists no official workaround, patching is the only remediation. Compensating controls that reduce attack surface in the meantime: restrict network access to the management interface to a small admin allowlist, disable the affected feature if it is not in use, and monitor the relevant logs for the exploitation patterns referenced in the advisory.

How to verify the fix worked

  1. Confirm the running version matches the patched build from the vendor advisory.
  2. Re-run your vulnerability scanner; the CVE should clear.
  3. Review logs from before the patch for the exploitation signatures described in the advisory, and treat any matches as a possible compromise (rotate credentials, isolate the host, full IR).

Frequently asked questions

Other vulnerabilities in the same area that are worth patching alongside this one:

Is CVE-2025-38352 being exploited right now?

Yes. It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-09-04), which means CISA has evidence of active exploitation.

What is the CVSS score for CVE-2025-38352?

CVSS 0.0. Use this with your own asset exposure to set patching priority (internet-exposed systems first).

Do I need to take the system offline to patch?

It depends on the platform. Many appliances support hitless upgrade in HA pairs (upgrade standby, fail over, upgrade primary). Servers and applications usually need a service restart. Plan a maintenance window if HA is not available.

What if my version is not listed as affected?

Cross-check against the vendor advisory linked below. The CVE record reflects the vendor's official affected-products list at publication time; later-discovered variants are added through the same advisory or a follow-up CVE.

References

*This guide was assembled from the official vendor advisory, NVD record, and CISA KEV listing on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*