Server-Side Request Forgery (SSRF) in Fluentd - CVE-2026-44161

 

Server-Side Request Forgery (SSRF) in Fluentd - CVE-2026-44161

Published: June 29, 2026


Vulnerability identifier: #VU135830
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:N]
CVE-ID: CVE-2026-44161
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to perform server-side request forgery.

The vulnerability exists due to server-side request forgery in the out_http endpoint configuration parameter when expanding placeholders derived from untrusted user input. A remote attacker can supply a crafted placeholder value to perform server-side request forgery.

This can cause outbound HTTP requests to be sent to internal services or cloud metadata endpoints.


Affected software

Fluentd

How to mitigate CVE-2026-44161

Install security update from vendor's website.

Fluentd - update to 1.19.3

External References

Related Security Bulletins