CVE-2025-12972: fluentbit fluent bit Path Traversal

Vulnerability summary

CVE-2025-12972 is a medium (CVSS 5.3) Path Traversal vulnerability in fluentbit fluent bit. EPSS estimates a 0.90% chance of exploitation in the next 30 days, higher than 58.9% of scored vulnerabilities.

Timeline

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

Description

Fluent Bit out_file plugin does not properly sanitize tag values when deriving output file names. When the File option is omitted, the plugin uses untrusted tag input to construct file paths. This allows attackers with network access to craft tags containing path traversal sequences that cause Fluent Bit to write files outside the intended output directory.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.