Fluent Bit maintains active security support for a limited set of release lines. Security updates are provided for the versions listed below until their End-of-Maintenance (EOM) dates.

Note: 4.2 and earlier are End-of-Life (EOL) and receive no further fixes. The v5.1 End-of-Maintenance date will be published when it is finalized.

• We backport critical and high-severity security fixes to all Active branches listed above.
• Medium/low-severity fixes may be backported at the maintainers’ discretion.
• After a branch reaches EOM, no further patches are published for that line.
• Users are strongly encouraged to use the latest 5.1.x release.

Please report suspected vulnerabilities privately:

• Email: fluentbit-security@googlegroups.com
• Include: affected versions, environment, clear reproduction steps, logs/traces, and impact assessment if known.

Please do not file public GitHub issues for security reports.

Response targets (best effort):

• Acknowledgement: within 72 hours
• Initial assessment: within 7 days
• Fix/Advisory: coordinated with reporter; timing depends on severity and scope

• We work with reporters to validate issues, develop fixes, and publish coordinated advisories.
• Public disclosure occurs once a fix or acceptable mitigation is available, or by mutual agreement.

• Security advisories and related notices are shared via:
  • GitHub Security Advisories on the Fluent Bit repo
  • GitHub Discussions: https://github.com/fluent/fluent-bit/discussions

For third-party CVEs that may impact Fluent Bit, we will post an assessment and any required guidance through the channels above.

Last updated: August 14, 2026