CVE-2025-12969: fluentbit fluent bit

Vulnerability summary

CVE-2025-12969 is a medium (CVSS 6.5) vulnerability in fluentbit fluent bit. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.6% of scored vulnerabilities.

Timeline

1. 24-11-2025
   PublishedVulnerability first disclosed.
2. 07-01-2026
   Last modifiedVulnerability information updated.

Description

Fluent Bit in_forward input plugin does not properly enforce the security.users authentication mechanism under certain configuration conditions. This allows remote attackers with network access to the Fluent Bit instance exposing the forward input to send unauthenticated data. By bypassing authentication controls, attackers can inject forged log records, flood alerting systems, or manipulate routing decisions, compromising the authenticity and integrity of ingested logs.

• CWE-306Missing Authentication for Critical FunctionThe product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.