CVE-2026-44161

Fluentd: Server-Side Request Forgery (SSRF) via Placeholder Expansion in `out_http`

HIGH
7.2
CVSS Score
Published: July 8, 2026 at 09:25 PM UTC
Updated: October 25, 2026 at 05:10 PM UTC
2 products affected across 2 vendorsFluentdFluentd

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Severity
HIGH7.2
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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, 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.19.3
Affected range stops below 1.19.3, so it looks safe — our inference, not a vendor statement
v < 1.19.3
Affected range stops below 1.19.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/fluent/fluentd/security/advisories/GHSA-72f5-rr8c-r6gr
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/fluent/fluentd/pull/5394
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/fluent/fluentd/releases/tag/v1.19.3

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
LOW
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-918

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