dbcve.org
Fluent BitApplication · Treasuredata

CVE-2025-12970

HIGH · 8.8 CVSS v3.1 Published 2025-11-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The extract_name function in Fluent Bit in_docker input plugin copies container names into a fixed size stack buffer without validating length. An attacker who can create containers or control container names, can supply a long name that overflows the buffer, leading to process crash or arbitrary code execution.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The extract_name function in Fluent Bit's in_docker input plugin copies container names into a fixed-size stack buffer without validating the name length first. An attacker who can create containers or control container names can supply an overly long name that overflows the buffer, leading to process crash or arbitrary code execution.

MitigationUpdate Fluent Bit to a patched version once available; until then, restrict who can create or control container names and apply network segmentation to limit exposure to untrusted container environments.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Fluent BitApplication
Affected:= 4.1.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Fluent Bit installation and version
    Run command: flb-version or fluent-bit --version to retrieve the installed Fluent Bit version
    Affected if Version is exactly 4.1.0 of Treasuredata Fluent Bit
  2. Determine if in_docker input plugin is in use
    Check Fluent Bit configuration files (fluent-bit.conf, *.conf in /etc/fluent-bit/) or running configuration for 'input' section referencing 'in_docker' or 'docker' plugin
    Affected if The in_docker input plugin is enabled and configured to collect container metadata
  3. Assess container name control scope
    Review who has permissions to create containers or modify container names in the environment (e.g., check Docker/Kubernetes RBAC policies, container runtime permissions, or orchestration access controls)
    Affected if Untrusted or external actors can create containers or supply container names that Fluent Bit will process
  4. Inspect for process crashes or anomalous behavior
    Review system logs (journalctl, syslog, /var/log/messages) and Fluent Bit service logs for segfaults, crashes, or unexpected termination events occurring around the in_docker plugin
    Affected if Fluent Bit process has crashed or exhibited unstable behavior, particularly after container creation events

A defender is affected if running Treasuredata Fluent Bit version 4.1.0 with the in_docker input plugin enabled and untrusted users can create or control container names that Fluent Bit processes.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update Fluent Bit to a patched version once available; until then, restrict who can create or control container names and apply network segmentation to limit exposure to untrusted container environments.

Recommended fix Moderate confidence

Fluent Bit 4.1.1 or latest stable 4.x release

  1. 1. Identify all systems running Fluent Bit 4.1.0 using package managers or container inventories
  2. 2. Stop the Fluent Bit service on each affected system before updating
  3. 3. Upgrade Fluent Bit to the latest stable release (recommended: version 4.1.1 or later if available, otherwise latest 4.x release)
  4. 4. Verify the upgrade was successful by checking the installed version with: fluent-bit --version
  5. 5. Restart the Fluent Bit service and confirm normal operation
  6. 6. Monitor logs for any errors related to the in_docker input plugin
Caveat Review release notes for any configuration or input plugin changes between 4.1.0 and the target version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Fluent Bit Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,970
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-12970 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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