by Kastro
Paper/Archive/CVE-2026-44024

CVE-2026-44024

fluent fluentd — Fluentd: Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder

EPSS 1%CVSS 9.8
critical.is priorityof 100
43
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 65.3.653 × 2013.1No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
fluentd< 1.19.3–CNA

Scores by source

GitHub_M (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/fluent/fluentd/security/advisories/GHSA-44hj-4m45-frj3refgithub.com/fluent/fluentd/pull/5391refgithub.com/fluent/fluentd/commit/45c87a81f3ac0b72b3f9dcfe8cfb5f9038f81437refgithub.com/fluent/fluentd/releases/tag/v1.19.3