CVE-2025-12969

Published Nov 24, 2025

Last updated 7 days ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2025-12969 affects the Fluent Bit in\_forward input plugin. Under specific configuration scenarios, the plugin doesn't properly enforce the security.users authentication mechanism. This flaw allows remote attackers with network access to the Fluent Bit instance to send unauthenticated data. By bypassing authentication controls, attackers can inject forged log records, flood alerting systems, or manipulate routing decisions. This can compromise the authenticity and integrity of ingested logs. Specifically, this occurs when Security.Users is configured without a Shared_Key, which silently disables authentication.

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.
Source: cret@cert.org
NVD status: Modified
Products: fluent_bit

Risk scores

CVSS 3.1

Type: Secondary
Base score: 6.5
Impact score: 2.5
Exploitability score: 3.9
Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity: MEDIUM

Weaknesses

nvd@nist.gov: CWE-306

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "negate": false,
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:treasuredata:fluent_bit:4.1.0:*:*:*:*:*:*:*",
            "vulnerable": true,
            "matchCriteriaId": "4D0EA105-B741-4E44-828A-9300B09A7A79"
          }
        ],
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.