Fluentd: Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder (fluent fluentd)
At a glance
- Source
- NVD
- EPSS
- EPSS 1.08 % · percentile 65 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
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 ${tag} in file configurations such as the path parameter of the out_file plugin allows attackers sending untrusted tags containing path traversal characters to write or overwrite arbitrary files and potentially achieve remote code execution. This issue is fixed in version 1.19.3.
Weaknesses (CWE)
- CWE-22 — Improper Limitation of a Pathname to a Restricted Directory
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | GitHub_M |
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-44hj-4m45-frj3 — Fluentd is Vulnerable to Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder
European references
- ENISA EUVD · EUVD-2026-42436
- GCVE · GCVE-0-2026-44024
CERT-FR advisories
- CERTFR-2026-AVI-0958 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:fluentd:fluentd:*:*:*:*:*:*:*:*< 1.19.3
Affected products
| Product | Versions |
|---|---|
| fluent · fluentd | affected < 1.19.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |