CVE-2025-38352
CVE-2025-38352 — Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability
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.
Published Updated Sources: NVD, CISA, FIRST EPSS
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Confirmed
CISA KEV, listed Sep 4, 2025
EPSS
1%
ahead of 69% of scored CVEs
CVSS base
7.4
high
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Remediation
The vendor's own words where we have them.
Upgrade linux to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
CISA 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.
Federal deadline Sep 25, 2025 — passed 370 days ago
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Treat as emergency remediation because CISA KEV status is present.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux | — | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
High
Confidentiality
High
Integrity
High
Scope
Unchanged
Attack Complexity
High
Attack Vector
Local
Privileges Req
None
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.4 | CVSS 3.1 | high | 1.4 | 5.9 | CNA |
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness & attack patterns
- CWE-367
Inferred from the weakness class — not observed against this CVE.
CISA KEV details
CISA lists a CVE here once it has evidence of exploitation against real targets.
Listed
Sep 4, 2025
Federal deadline
Sep 25, 2025
passed 370 days ago
Ransomware use
Unknown
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Exploit entries
1
Exploit-DB and CTI exploit indexes
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /or.
- Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 7.4 (AV:L)
Jun 17, 2026 · NVD
- 2025
Added to CISA KEV catalog
Sep 4, 2025 · CISA
Initial · CVE published
Jul 22, 2025 · NVD
References
15 on the record
- git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff
Patch
- git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b
Patch
- git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b
Patch
- git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb
Patch
- git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200
Patch
- git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b
Patch
- git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7
Patch
- git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca
Patch
Elsewhere on this site
- linuxevery CVE for this vendor
- September 2025what else CISA listed
- Race Conditionsame class
- CWE-367other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2025-38352 is Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability, a high vulnerability affecting linux from linux. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.4 describes technical severity, while EPSS 1% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.