VulnerabilityPublished 20 Mar 2026

CVE-2026-31836: bluewave-labs Checkmate · Improper Authorization

Affects bluewave-labs CheckmateSource CVE Database V5

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Not known to be exploited · CVSS 8.1 High.

Data as of 1 Nov 2026, 11:02 UTC

CVSS 3.1 base score

8.1High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 1 Nov 2026.

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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity 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

Affected software

Product	Affected	Fixed in
bluewave-labsCheckmate	Affected <=3.5.1	Fixed in–
GitHubbluewave-labs/Checkmate`pkg:github/bluewave-labs/Checkmate`Other threats	Affected <=3.5.1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until an official patch is released, organizations should implement specific mitigations to reduce risk. First, restrict access to the Checkmate application to trusted users only and enforce strong authentication mechanisms to limit the pool of potential attackers. Review and minimize the number of users with authenticated access, especially those with low privileges who could exploit the vulnerability. Employ network segmentation and firewall rules to limit access to the Checkmate server from untrusted networks. Monitor application logs for unusual user profile update requests or role changes. If possible, disable or restrict the user profile update endpoint temporarily or implement custom input validation to prevent role attribute modifications. Consider deploying a Web Application Firewall (WAF) with rules to detect and block mass assignment attempts targeting role attributes. Maintain heightened monitoring for suspicious activity until a vendor patch is available and promptly apply updates once released. Engage with bluewave-labs or the open-source community for updates or unofficial patches.

Description

Checkmate is an open-source, self-hosted tool designed to track and monitor server hardware, uptime, response times, and incidents in real-time with beautiful visualizations. In versions from 3.5.1 and prior, a mass assignment vulnerability in Checkmate's user profile update endpoint allows any authenticated user to escalate their privileges to superadmin, bypassing all role-based access controls. An attacker can modify their user role to gain complete administrative access to the application, including the ability to view all users, modify critical configurations, and access sensitive system data. At time of publication, there are no publicly available patches.

Impact

The impact of CVE-2026-31836 is significant for organizations using Checkmate for server and infrastructure monitoring. An attacker exploiting this vulnerability can gain full administrative privileges, compromising the confidentiality and integrity of monitoring data and user information. This could lead to unauthorized disclosure of sensitive operational data, manipulation or deletion of monitoring configurations, and potential disruption of incident response processes. Since Checkmate is often used to track uptime and incidents, tampering with its data could mask ongoing attacks or failures, delaying detection and remediation. The vulnerability does not directly affect availability but indirectly increases risk by undermining trust in monitoring systems. Organizations with large or critical infrastructure deployments relying on Checkmate are at heightened risk, especially if they have multiple authenticated users with low privileges who could exploit this flaw. The lack of available patches increases exposure time, necessitating immediate compensating controls.

CWE-285Improper Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
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 you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply 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
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Directory Indexing (opens in a new tab)
Subverting Environment Variable Values (opens in a new tab)
Using Malicious Files (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-269Improper Privilege Management (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Separation of Privilege
Follow the principle of least privilege when assigning access rights to entities in a software system.
Architecture and Design · Separation of Privilege
Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
Attack patterns
Restful Privilege Elevation (opens in a new tab)
Privilege Abuse (opens in a new tab)
Privilege Escalation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/bluewave-labs/Checkmate/security/advisories/GHSA-6368-x7wr-wpm2 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 20 Mar 2026, 21:36 UTC

WeaknessesCWE-285, CWE-269

Technical details

References

Community reviews

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