CVE-2025-12978
CVE-2025-12978
Description
Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins contain a flaw in the tag_key validation logic that fails to enforce exact key-length matching. This allows crafted inputs where a tag prefix is incorrectly treated as a full match. A remote attacker with authenticated or exposed access to these input endpoints can exploit this behavior to manipulate tags and redirect records to unintended destinations. This compromises the authenticity of ingested logs and can allow injection of forged data, alert flooding and routing manipulation.
INFO
Published Date :
Nov. 24, 2025, 3:15 p.m.
Last Modified :
Nov. 24, 2025, 4:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2025-12978
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Fluent Bit to a fixed version.
- Restrict access to input endpoints.
- Monitor logs for suspicious tag manipulation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-12978.
| URL | Resource |
|---|---|
| https://fluentbit.io/announcements/v4.1.0/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-12978 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-12978
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-12978 vulnerability anywhere in the article.
-
The Register
Years-old bugs in open source tool left every major cloud open to disruption
A series of "trivial-to-exploit" vulnerabilities in Fluent Bit, an open source log collection tool that runs in every major cloud and AI lab, was left open for years, giving attackers an exploit chain ... Read more
-
The Hacker News
New Fluent Bit Flaws Expose Cloud to RCE and Stealthy Infrastructure Intrusions
Nov 24, 2025Ravie LakshmananVulnerability / Container Security Cybersecurity researchers have discovered five vulnerabilities in Fluent Bit, an open-source and lightweight telemetry agent, that coul ... Read more
The following table lists the changes that have been made to the
CVE-2025-12978 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 24, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L -
New CVE Received by [email protected]
Nov. 24, 2025
Action Type Old Value New Value Added Description Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins contain a flaw in the tag_key validation logic that fails to enforce exact key-length matching. This allows crafted inputs where a tag prefix is incorrectly treated as a full match. A remote attacker with authenticated or exposed access to these input endpoints can exploit this behavior to manipulate tags and redirect records to unintended destinations. This compromises the authenticity of ingested logs and can allow injection of forged data, alert flooding and routing manipulation. Added Reference https://fluentbit.io/announcements/v4.1.0/