CVE-2026-44024 is a critical-severity path traversal vulnerability in fluentd (rubygems), affecting versions <= 1.19.2. It is fixed in 1.19.3.
Fluentd allows dynamically constructing file paths using the ${tag} placeholder. It was discovered that validation for this placeholder was insufficient. If a Fluentd instance is configured to receive logs from untrusted sources and uses the ${tag} placeholder in file configurations (such as the path parameter in the outfile plugin), an attacker can inject path traversal characters (e.g., ../). When combined with certain formatting options, this vulnerability allows an attacker to write arbitrary files or overwrite existing files on the system with attacker-controlled content, bypassing intended directory restrictions. Impact This vulnerability allows for Arbitrary File Write, which can be directly escalated to full Remote Code Execution (RCE). An attacker could achieve RCE by overwriting critical system files, injecting executable plugins, or modifying configuration files. The impact is Critical as it can lead to full system compromise without any authentication, depending on the Fluentd configuration and the privileges of the Fluentd process. Patches v1.19.3 Workarounds If an immediate upgrade is not possible, users are strongly advised to apply the following mitigations: Restrict Network Access Ensure that Fluentd input ports (such as inforward on default port 24224) are deployed within a closed, trusted network. Use firewall rules (e.g., iptables, AWS Security Groups) to block access from untrusted networks or instances. Run Fluentd as a non-root user Dropping privileges prevents Fluentd from writing to sensitive system directories (e.g., /etc/), significantly mitigating the risk of system-wide RCE. Revise configurations Do not use the ${tag} placeholder in the path parameter of output plugins (like out_file) if the tag originates from an untrusted source. Filter incoming tags Strictly validate and filter incoming tags at the input layer (e.g., using fluent-plugin-rewrite-tag-filter) to drop any tags containing . or / characters.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-44024 has a CVSS score of 9.8 (Critical). 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.
rubygems
fluentd (<= 1.19.2)fluentd → 1.19.3 (rubygems)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.
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Already deployed Kodem? See CVE-2026-44024 in your environment →Upgrade fluentd to 1.19.3 or later to resolve this vulnerability.
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CVE-2026-44024 is a critical-severity path traversal vulnerability in fluentd (rubygems), affecting versions <= 1.19.2. It is fixed in 1.19.3. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
CVE-2026-44024 has a CVSS score of 9.8 (Critical). 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.
fluentd (rubygems) versions <= 1.19.2 is affected.
Yes. CVE-2026-44024 is fixed in 1.19.3. Upgrade to this version or later.
Whether CVE-2026-44024 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
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.
Upgrade fluentd to 1.19.3 or later.