Summary
Fluentd is Vulnerable to Exposure of Sensitive Information via Monitor Agent API
Fluentd's Monitor Agent plugin (in_monitor_agent) exposes internal metrics and plugin information via a REST API.
It was discovered that the API response (/api/plugins.json and related endpoints) unintentionally includes internal instance variables of loaded plugins.
If any plugins store sensitive information, such as database passwords, API keys, or cloud credentials, in its instance variables,
this information may be exposed in plain text to any user or system that has HTTP access to the Monitor Agent API.
Workarounds
If usesrs cannot immediately update Fluentd to the patched version, they can mitigate this risk by strictly controlling access to the Monitor Agent port.
Ensure the Monitor Agent is only bound to localhost (127.0.0.1) rather than 0.0.0.0.
<source>
@type monitor_agent
bind 127.0.0.1
port 24220
</source>
Use firewall rules (e.g., iptables, AWS Security Groups) to block access to the Monitor Agent port (24220) from untrusted networks or instances.
Impact
This vulnerability allows for unauthorized information disclosure. An attacker who can reach the Monitor Agent API port (default: 24220) can potentially extract sensitive credentials used by other Fluentd plugins.
The impact severity depends highly on the network configuration (whether the Monitor Agent port is exposed to untrusted networks) and the specific plugins configured in the Fluentd instance.
A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.
CVE-2026-44025 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.19.3); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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v1.19.3
Frequently Asked Questions
- What is CVE-2026-44025? CVE-2026-44025 is a high-severity missing authentication for critical function vulnerability in fluentd (rubygems), affecting versions <= 1.19.2. It is fixed in 1.19.3. A critical operation is accessible without requiring any authentication.
- How severe is CVE-2026-44025? CVE-2026-44025 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of fluentd are affected by CVE-2026-44025? fluentd (rubygems) versions <= 1.19.2 is affected.
- Is there a fix for CVE-2026-44025? Yes. CVE-2026-44025 is fixed in 1.19.3. Upgrade to this version or later.
- Is CVE-2026-44025 exploitable, and should I be worried? Whether CVE-2026-44025 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-44025 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-44025? Upgrade
fluentdto 1.19.3 or later.