CVE-2026-44160 is a high-severity security vulnerability in fluentd (rubygems), affecting versions <= 1.19.2. It is fixed in 1.19.3.
Fluentd's inhttp and inforward plugins support receiving gzip-compressed data. While Fluentd correctly enforces size limits on the incoming compressed payloads (e.g., via bodysizelimit or chunksizelimit), it was discovered that there is no limit enforced on the size of the decompressed data. If a Fluentd instance is exposed to untrusted networks, an attacker can send a maliciously crafted, highly compressed payload. When Fluentd attempts to decompress this payload in memory, it will expand to an excessive size, completely bypassing the intended payload size limits. Impact This vulnerability allows for a Denial of Service (DoS) attack via memory exhaustion. The rapid memory consumption during decompression can easily lead to an Out-of-Memory kill of the Fluentd process by the operating system. This results in the disruption of all log collection and forwarding capabilities on the affected node. 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 9880 for inhttp and 24224 for inforward) are deployed within a closed, trusted network. Use firewall rules (e.g., iptables, AWS Security Groups) to block access from untrusted networks or instances. Use a Reverse Proxy If developers must expose HTTP ingestion to external sources, place a robust reverse proxy (such as Nginx) in front of Fluentd. Configure the proxy to handle the gzip decompression and enforce strict limits on both compressed and uncompressed body sizes before passing the traffic to Fluentd.
CVE-2026-44160 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.
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-2026-44160 in your environment →Upgrade fluentd to 1.19.3 or later to resolve this vulnerability.
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CVE-2026-44160 is a high-severity security vulnerability in fluentd (rubygems), affecting versions <= 1.19.2. It is fixed in 1.19.3.
CVE-2026-44160 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.
fluentd (rubygems) versions <= 1.19.2 is affected.
Yes. CVE-2026-44160 is fixed in 1.19.3. Upgrade to this version or later.
Whether CVE-2026-44160 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.