CVE-2026-44024
Fluentd: Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder
CVSS Score
9.8
EPSS Score
1.1%
EPSS Percentile
62th
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.
| CWE | CWE-22 |
| Vendor | fluent |
| Product | fluentd |
| Published | Jul 8, 2026 |
| Last Updated | Jul 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
fluent / fluentd
< 1.19.3
References
github.com: https://github.com/fluent/fluentd/security/advisories/GHSA-44hj-4m45-frj3 github.com: https://github.com/fluent/fluentd/pull/5391 github.com: https://github.com/fluent/fluentd/commit/45c87a81f3ac0b72b3f9dcfe8cfb5f9038f81437 github.com: https://github.com/fluent/fluentd/releases/tag/v1.19.3