What is CVE-2025-38352?A high-severity flaw criminals are using now.
CVE-2025-38352 is a high-severity flaw (CVSS 7.4) in Linux kernel, published on 22 July 2025. It is on the list of flaws known to be exploited, so criminals are already using it. The latest forecast puts its chance of use in the next 30 days at 1.3%. If you run an affected version, patch it first.
Published 22 July 2025. Record last updated 5 September 2025. We keep this page's data up to date.
What is CVE-2025-38352? In plain terms.
An attacker has to be already on the device without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.
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.
What kind of flaw is it?
- CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAlready on the device
- How hard it is to pull offHard: conditions must line up
- Login needed firstNo login needed
- Does someone have to clickNo, nobody has to do anything
- What an attacker getsCan read data, change data and take it offline
Severity vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Is CVE-2025-38352 being exploited? Yes.
Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 1.3%.
Timeline
- Published
- Added to the known-exploited list
- Record last updated
CVE-2025-38352 scores 74. Action: Emergency patch.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isKey context
- Real threat activity around itKey context
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2025-38352 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2025-38352? One product.
The published record lists 1 product from 1 vendor. Versions are shown as published: "2.6.36 to before 5.4.295" means from 2.6.36 up to, but not including, 5.4.295. If you run one of these, check your version, then go to the fix below.
- Operating system
Linux kernel
by Linux
Affected versions2.6.36 to before 5.4.2955.5 to before 5.10.2395.11 to before 5.15.1865.16 to before 6.1.1426.2 to before 6.6.946.7 to before 6.12.346.13 to before 6.15.36.16-rc1
How do I fix CVE-2025-38352? Four steps.
- Check whether you run itCompare your versions with the affected products above. Not sure what you run? EdgeProtect can work it out from your public website, or you can pick it from a list.
- Apply the vendor’s fixInstall the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Check it wasn’t used before you patchedBecause criminals are already using this flaw, look for signs of a break-in on affected systems using the vendor’s guidance.
Does CVE-2025-38352 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
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1 flaw being exploited affects software Acme tracks
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...
- Matched to
- Linux kernel on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2025-38352 is a high-severity flaw in Linux kernel, published on 22 July 2025. An attacker has to be already on the device without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.
It scores 7.4 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2025-38352 is 74 out of 100, which is High. Its action is "Emergency patch". Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.
Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 1.3%.
For Linux kernel: 2.6.36 to before 5.4.295, 5.5 to before 5.10.239, 5.11 to before 5.15.186, 5.16 to before 6.1.142, 6.2 to before 6.6.94, 6.7 to before 6.12.34 and 2 more.
Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. Because criminals are already using it, also check affected systems for signs of a break-in.