CVE-2025-38352
Linux Kernel: Time-of-Check Time-of-Use (TOCTOU) Race Condition
As of , CVE-2025-38352 in Linux Kernel is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch soon.
- Exploited
- Yes: CISA listed it on 4 September 2025
- US federal deadline
- 25 September 202521 days after CISA listed it. US federal civilian agencies must fix it by then.
- Used in ransomware campaigns
- Not known to CISA
- EPSS score
- 0.01Higher than 69% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
- Public exploit
- None foundNeither Metasploit nor Exploit-DB lists one.
- Fix
- Vendor advice: git.kernel.org and source.android.comLinks below, from CISA's entry.
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA's required action
- git.kernel.orgThis vulnerability affects a common open-source component, third-party library, or a protocol used by different products. Please check…
- source.android.com
What the flaw is
Linux kernel contains a time-of-check time-of-use (TOCTOU) race condition vulnerability that has a high impact on confidentiality, integrity, and availability.
CISA's description
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.
The CVE record's description, from Linux
- CVE published
- 22 July 2025
- Assigned by
- Linux
- CVSS
- 7.8 High (CVSS 3.1, from the CNA)
- CWE-367
- Time-of-check Time-of-use (TOCTOU) Race Condition
- CISA SSVC, exploitation
- active
- CISA SSVC, automatable
- no
- CISA SSVC, technical impact
- total
Timeline
- The CVE record was published.
- CISA added it to its list of exploited vulnerabilities.
- The US federal deadline to fix it.
Kernel: other exploited entries
| Vulnerability | Product | Our group | Listed | Deadline | EPSS |
|---|---|---|---|---|---|
| CVE-2025-39682Improper Check for Unusual or Exceptional Conditions | Linux Kernel | Patch nowForensic triage required by CISA | 0.03 | ||
| CVE-2025-39964Race Condition | Linux Kernel | Patch nowForensic triage required by CISA | 0.01 | ||
| CVE-2026-53266Out-of-Bounds Write | Linux Kernel | Patch nowForensic triage required by CISA | 0.01 | ||
| CVE-2026-53362Unspecified | Linux Kernel | Patch nowForensic triage required by CISA | 0.01 | ||
| CVE-2021-22555Heap Out-of-Bounds Write | Linux Kernel | Patch this weekMetasploit module; EPSS 0.79; verified Exploit-DB entry | 0.79 | ||
| CVE-2013-6282Improper Input Validation | Linux Kernel | Patch this weekMetasploit module; verified Exploit-DB entry | 0.40 | ||
| CVE-2019-13272Improper Privilege Management | Linux Kernel | Patch this weekMetasploit module; EPSS 0.52; verified Exploit-DB entry | 0.52 | ||
| CVE-2010-3904Improper Input Validation | Linux Kernel | Patch this weekMetasploit module; verified Exploit-DB entry | 0.16 | ||
| CVE-2022-0847Privilege Escalation | Linux Kernel | Patch this weekMetasploit module; EPSS 0.93 | 0.93 | ||
| CVE-2021-3493Privilege Escalation | Linux Kernel | Patch this weekMetasploit module | 0.49 |
Read further
- CVE recordcve.org
- NVD entrynvd.nist.gov
- CISA's catalogcisa.gov
- EPSS for this CVEapi.first.org