CVE-2026-44161
Fluentd: Server-Side Request Forgery (SSRF) via Placeholder Expansion in `out_http`
CVSS Score
7.2
EPSS Score
0.4%
EPSS Percentile
36th
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, the Fluentd out_http output plugin allows placeholders such as ${tag} in the endpoint configuration parameter, and if a placeholder value is derived from untrusted input an attacker can control the destination hostname of outbound HTTP requests and force requests to arbitrary internal services. This issue is fixed in version 1.19.3.
| CWE | CWE-918 |
| Vendor | fluent |
| Product | fluentd |
| Published | Jul 8, 2026 |
| Last Updated | Jul 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
Low
Affected Versions
fluent / fluentd
< 1.19.3
References
github.com: https://github.com/fluent/fluentd/security/advisories/GHSA-72f5-rr8c-r6gr github.com: https://github.com/fluent/fluentd/pull/5394 github.com: https://github.com/fluent/fluentd/commit/c6a01ea2e0ea01977f8d615f7c6dbfae4cba88c9 github.com: https://github.com/fluent/fluentd/releases/tag/v1.19.3