CVE-2026-24095VulnerabilityPublished 9 Feb 2026

CVE-2026-24095: Checkmk · Missing Authorization

Affects CheckmkSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 2.4.0p21 or 2.3.0p43 when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.4.0p21, 2.3.0p43

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Checkmk to 2.4.0p21 or 2.3.0p43.

Affected software

Product	Affected	Fixed in
Checkmk GmbHCheckmk	Affected >=2.4.0 <2.4.0p21 >=2.3.0 <2.3.0p43 =2.2.0	Fixed in 2.4.0p21 2.3.0p43

AI-suggested

1. Upgrade affected Checkmk instances to the latest patched versions: 2.4.0p21 or 2.3.0p43, or later releases where this authorization issue is resolved. 2. Conduct a thorough audit of user permissions within Checkmk, ensuring that the 'Use WATO' and 'Make changes, perform actions' permissions are granted only to trusted administrators with a clear operational need. 3. Implement the principle of least privilege by segregating duties so that users with 'Use WATO' permission do not simultaneously have change management permissions. 4. Monitor access logs and configuration changes within Checkmk to detect any unauthorized access or suspicious activity related to the 'Analyze configuration' page. 5. If immediate patching is not feasible, restrict network access to the Checkmk web interface to trusted IP ranges and enforce strong authentication mechanisms. 6. Educate administrators and users about the risks of improper permission assignments and encourage regular reviews of access controls. 7. Integrate Checkmk monitoring with centralized SIEM solutions to correlate events and detect potential misuse.

Description

Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p21, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows users with the "Use WATO" permission to access the "Analyze configuration" page by directly navigating to its URL, bypassing the intended "Access analyze configuration" permission check. If these users also have the "Make changes, perform actions" permission, they can perform unauthorized actions such as disabling checks or acknowledging results.

Impact

For European organizations, this vulnerability poses a risk to the integrity and reliability of IT infrastructure monitoring. Unauthorized access to configuration analysis and the ability to disable checks or acknowledge alerts can lead to undetected system failures, delayed incident response, and potential operational disruptions. Critical sectors such as finance, healthcare, energy, and telecommunications that rely heavily on continuous monitoring could experience degraded security posture and operational risks. The ability to manipulate monitoring results may also facilitate further attacks by masking malicious activity. Since Checkmk is used for centralized monitoring, exploitation could affect multiple systems simultaneously, increasing the scope of impact. The medium severity rating indicates that while the vulnerability is not critical, it still requires timely remediation to maintain trust in monitoring data and ensure compliance with regulatory requirements such as GDPR, which mandates robust security controls.

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

checkmk.com/werk/19032 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Feb 2026, 16:15 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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