CISA KEV High Logic error exploit reference

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 Jul 22, 2025 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories, NIST National Vulnerability Database · CNA: Linux

High

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Sep 4, 2025 Proofs of concept on GitHub · 6

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Public exploit/PoC (github)+6
EPSS 1.3% (30-day exploitation probability)+11
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Sep 4, 2025

EPSS FIRST

1.34%

ahead of 71% of scored CVEs · Oct 14, 2026

Affects

Debian

Debian Linux and 2 more

CVSS base

7.8

High · 3 source(s)

CISA SSVC assessment CISA

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

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

CISA required action CISA

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

US federal deadline: Sep 25, 2025 — passed 385 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Debian	Debian Linux	version 11.0	Vulnerable	NIST National Vulnerability Database
Linux	Linux	≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < 78a4b8e3795b31dae58762bc091bb0f4f74a2200version 2.6.36≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < f90fff1e152dedf52b932240ebbd670d83330eca≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < 460188bc042a3f40f72d34b9f7fc6ee66b0b757b≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < c29d5318708e67ac13c1b6fc1007d179fb65b4d7≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < 764a7a5dfda23f69919441f2eac2a83e7db6e5bb≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < 2f3daa04a9328220de46f0d5c919a6c0073a9f0b and 1 more ≥ 0bdd2ed4138ec04e09b4f8165981efc99e439f55 and < c076635b3a42771ace7d276de8dc3bc76ee2ba1b	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	version 6.16-rc1≥ 6.13 and < 6.15.3≥ 6.7 and < 6.12.34≥ 6.2 and < 6.6.94≥ 5.16 and < 6.1.142≥ 5.11 and < 5.15.186≥ 5.5 and < 5.10.239≥ 2.6.36 and < 5.4.295	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 3.1	High	1.8	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP
7.4	CVSS 3.1	High	—	—	GitHub, Inc. via GitHub Security Advisories

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Sources assign different scores within the same severity band. For prioritization we use 7.8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-367 · TOCTOU Race Condition

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Sep 4, 2025

Federal deadline

Sep 25, 2025

passed 385 day(s) 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 reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Proofs of concept on GitHub

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 1.34%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Hunt retroactively in logs from before Sep 4, 2025 (KEV listing): exploitation may have started earlier.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · linux/linux kernel, debian/debian linux
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · Published → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record published
Oct 13, 2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
CVSS changed · 7.8
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Published
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
2025
Added to CISA KEV catalog
Sep 3, 2025 · CISA
CVE published
Jul 22, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

14 on the record

git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca
Patch, CVE Program (cve.org) e CISA ADP
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, GitHub Security Advisories
lists.debian.org/debian-lts-announce/2025/10/msg00007.html
Mailing List, Third Party Advisory, GitHub Security Advisories
lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Mailing List, Third Party Advisory, GitHub Security Advisories
github.com/advisories/GHSA-mr4j-mh66-4679
GitHub Security Advisories
github.com/farazsth98/chronomaly
Exploit, GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2025-38352
GitHub Security Advisories

Elsewhere on this site

Debian
every CVE for this vendor

2025-09
what else CISA listed that month

Logic error
same class

CWE-367
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

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 record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-38352 is "Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 1.34% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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