SecuriTricks - CVE-2025-12969

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.

Product(s) Impacted

Vendor	Product	Versions
Treasuredata	Fluent Bit	4.1.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-306

Missing Authentication for Critical Function

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	treasuredata	fluent_bit	4.1.0	/	/	/	/	/	/	/

References

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

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

CVSS Score

6.5 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: LOW
Privileges Required: NONE
Scope: UNCHANGED
Confidentiality Impact: LOW
Integrity Impact: LOW
Availability Impact: NONE

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

View Vector String

Timeline

Published: Nov. 24, 2025, 3:15 p.m.
Last Modified: Nov. 28, 2025, 6:15 p.m.

Status : Modified

CVE has been amended by a source (CVE Primary CNA or another CNA). Analysis data supplied by the NVD may be no longer be accurate due to these changes.

More info

Source

cret@cert.org

CVE-2025-12969