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CVE-2025-12969· NVD / CVE Program· CNA certcc

Fluent Bit in_forward input plugin does not properly enforce the security.users authentication mechanism under certain configuration conditi

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.61% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: azl3 fluent-bit 3.1.10-2 on Azure Linux 3.0 3.1.10-3; cbl2 fluent-bit 3.0.6-4 on CBL Mariner 2.0 3.0.6-6.

Low priority for now. Upgrade to azl3 fluent-bit 3.1.10-2 on Azure Linux 3.0 3.1.10-3; cbl2 fluent-bit 3.0.6-4 on CBL Mariner 2.0 3.0.6-6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 6.5 · v3.1—No exploit Fix available
Published
Nov 24, 2025
Updated
Oct 8, 2026
EPSS
0.6% · 48th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-12969

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
treasuredatafluent bit

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • treasuredata fluent bit4.1.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (certcc). Independent of NVD's CPE analysis and usually ahead of it.

  • FluentBit Fluent Bit

    • before 4.0.13affected

Same product

treasuredata: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-4323Fluent Bit Memory Corruption Vulnerability
    47Plan
  • CVE-2021-36088Fluent Bit (aka fluent-bit) 1.7.0 through 1.7.4 has a double free in flb_free (called from flb_parser_json_do and flb_parser_do).
    40Plan
  • CVE-2025-12977Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins fail to sanitize tag_key inputs.
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-29477Apr 4, 2025 · An issue in fluent-bit v.3.7.2 allows a local attacker to cause a denial of service via the function consume_event.
    22Monitor
  • ← EarlierCVE-2025-29478Apr 7, 2025 · An issue in fluent-bit v.3.7.2 allows a local attacker to cause a denial of service via the cfl_list_size in cfl_list.h:165.
    22Monitor
  • Later →CVE-2025-12970Nov 24, 2025 · The extract_name function in Fluent Bit in_docker input plugin copies container names into a fixed size stack buffer without validating leng
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 fluent-bit 3.1.10-2 on Azure Linux 3.03.1.10-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 fluent-bit 3.0.6-4 on CBL Mariner 2.03.0.6-6 · CBL-Mariner ReleasesMicrosoft (MSRC)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2025-129700 days apartThe extract_name function in Fluent Bit in_docker input plugin copies container names into a fixed size stack buffer without validating leng
    35Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

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

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
// Added for the support teamapp.post("/maintenance/reset", resetDevice);

Fixed

ts
if (config.maintenanceEnabled) {  app.post(    "/maintenance/reset",    requireSession, requireRole("admin"), resetDevice  );}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records