CVE-2025-12972

Published: Nov 24, 2025Modified: Nov 28, 2025

5.3

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Exploitability: 3.9 / Impact: 1.4

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

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.

Affected (1)

Products: Treasuredata: Fluent Bit

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Treasuredata Fluent Bit	Version 4.1.0

Related CWEs

Improper 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.

References (2)

https://fluentbit.io/blog/2025/10/28/security-vulnerabilities-addressed-in-fluent-bit-v4.1-and-backported-to-v4.0/

Source: cret@cert.org

https://www.oligo.security/blog/critical-vulnerabilities-in-fluent-bit-expose-cloud-environments-to-remote-takeover

Source: cret@cert.org

Timeline

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