Medium Access control

CVE-2025-64996 — Overly broad file permissions in the mk_inotify plugin allows reading and manipulating the plugin's output

In Checkmk versions prior to 2.4.0p16, 2.3.0p41, and all versions of 2.2.0 and older, the mk_inotify plugin creates world-readable and writable files, allowing any local user on the system to read the plugin's output and manipulate it, potentially leading to unauthorized access to or modification of monitoring data.

Published Nov 18, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Checkmk

Low

Who exploits it and how urgent it is

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

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (30-day exploitation probability)+0
Technical severity (medium)+3

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

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.1%

ahead of 1% of scored CVEs · Oct 14, 2026

Affects

Checkmk

CVSS base

4.4

Medium · 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

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

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

Documented mitigation — checkmk.com (NIST National Vulnerability Database)

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 (Checkmk Checkmk).
Apply the documented mitigations until a definitive fix is available.
Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Checkmk	Checkmk	version 2.3.0-p8version 2.4.0-p1version 2.4.0-b6version 2.4.0-b5version 2.4.0-b4version 2.4.0-b3version 2.4.0-b2version 2.4.0-b1 and 62 more version 2.4.0version 2.3.0-p9version 2.4.0-p10version 2.3.0-p7version 2.3.0-p6version 2.3.0-p5version 2.3.0-p40version 2.3.0-p4version 2.3.0-p39version 2.3.0-p38version 2.3.0-p37version 2.4.0-p5version 2.4.0-p9version 2.4.0-p8version 2.4.0-p7version 2.4.0-p6version 2.3.0-p36version 2.4.0-p4version 2.4.0-p3version 2.4.0-p2version 2.4.0-p15version 2.4.0-p14version 2.4.0-p13version 2.4.0-p12version 2.4.0-p11version 2.3.0-p10version 2.3.0-p19version 2.3.0-p18version 2.3.0-p17version 2.3.0-p16version 2.3.0-p15version 2.3.0-p14version 2.3.0-p13version 2.3.0-p12version 2.3.0-p11version 2.3.0-p2version 2.3.0-p1version 2.3.0-b6version 2.3.0-b5version 2.3.0-b4version 2.3.0-b3version 2.3.0-b2version 2.3.0-b1version 2.3.0version 2.3.0-p28version 2.3.0-p35version 2.3.0-p34version 2.3.0-p33version 2.3.0-p32version 2.3.0-p31version 2.3.0-p30version 2.3.0-p3version 2.3.0-p29< 2.3.0version 2.3.0-p27version 2.3.0-p26version 2.3.0-p25version 2.3.0-p24version 2.3.0-p23version 2.3.0-p22version 2.3.0-p21version 2.3.0-p20	Vulnerable	NIST National Vulnerability Database
Checkmk	Checkmk	version 2.1.0version 2.2.0≥ 2.3.0 and < 2.3.0p41≥ 2.4.0 and < 2.4.0p16	Vulnerable	CVE Program (cve.org) e CISA ADP

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

Low

Integrity

Low

Availability

None

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
4.8	CVSS 4.0	Medium	—	—	security@checkmk.com via NIST National Vulnerability Database
4.8	CVSS 4.0	Medium	—	—	Checkmk via CVE Program (cve.org) e CISA ADP
4.4	CVSS 3.1	Medium	1.8	2.5	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-732 · Incorrect Permission Assignment for Critical Resource

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.10%

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.
Audit administrative actions and access to resources outside each user’s normal pattern.

endpoint telemetry (EDR)authentication logsapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · checkmk gmbh/checkmk
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 4.4
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2025
CVE published
Nov 18, 2025 · Checkmk

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

checkmk.com/werk/18570
Mitigation, Vendor Advisory, NIST National Vulnerability Database

Elsewhere on this site

Checkmk
every CVE for this vendor

Access control
same class

CWE-732
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-105331 mk-oracle: Local privilege escalation via malicious Oracle Instant Client 7d
Medium CVE-2026-15227 Missing Authorization Allows Editing of Foreign Reports Jul 31, 2026
Medium CVE-2026-8593 Fix Business Intelligence API Pack permission Jul 21, 2026
Medium CVE-2026-14852 mk_sap_hana: Privilege escalation via crafted sapstartsrv process name Jul 14, 2026
Medium CVE-2026-9549 Fix XSS in service discovery active check output Jun 8, 2026
Medium CVE-2026-7186 Fix stored XSS in URL dashboard widget via dangerous URI schemes Jun 8, 2026

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-2025-64996 is "Overly broad file permissions in the mk_inotify plugin allows reading and manipulating the plugin's output", rated Medium. It affects Checkmk (Checkmk); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.4 describes technical severity. EPSS 0.10% 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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