CVE-2026-44024 Fluentd: Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder
Attackers can achieve remote code execution by sending malicious tags to write arbitrary files via path traversal in Fluentd's file output plugin.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44024?
CVE-2026-44024 is a critical path traversal vulnerability in fluentd, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on. Prior to 1.19.3, Fluentd allows dynamically constructing file paths using the ${tag} placeholder, and insufficient validation of ${tag} in file configurations such as the path parameter of the out_file plugin allows attackers sending untrusted tags containing path traversal characters to write or overwrite arbitrary files and potentially achieve remote code execution. This issue is fixed in version 1.19.3.
Weakness: CWE-22
Which versions are affected by CVE-2026-44024?
3 open source packages ship an affected version, including fluentd. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
fluentd Bitnami | All versions | 1.19.3 |
fluentd RubyGems | All versions | 1.19.3 |
fluentd RubyGems | All versions | 1.19.3 |
Products include Fluentd Fluentd.
How do I fix CVE-2026-44024?
Upgrade fluentd to 1.19.3 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-44024 being exploited?
There is no known exploitation of CVE-2026-44024 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in fluentd
- CVE-2017-10906 Fluentd Escape Sequence Injection Vulnerability
- CVE-2020-21514 Fluent Fluentd and Fluent-ui use default password
- CVE-2026-44025 Fluentd: Exposure of Sensitive Information via Monitor Agent API
- CVE-2026-44160 Fluentd: Denial of Service (DoS) via Gzip Decompression Bomb in `in_http` and `in_forward`
- CVE-2026-44161 Fluentd: Server-Side Request Forgery (SSRF) via Placeholder Expansion in `out_http`
Sources
Also known as BIT-fluentd-2026-44024, CLEANSTART-2026-EN06234, GHSA-44hj-4m45-frj3, MINI-2f53-xj9m-qx8c, MINI-6mcw-c5gv-m95w, MINI-84xv-wqvw-869x and 13 more.