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Vulnerability record · CVE-2025-12969 · published 24 November 2025

CVE-2025-12969: Treasuredata fluent bit missing authentication for critical function vulnerability

Treasuredata · Fluent Bit

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.

6.5 CVSS 3.1 Medium EPSS 0.61% · top 52.8% CWE-306 · Missing authentication for critical function
6.5CVSS 3.1 base score
0.61%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-12969), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.