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.
Metrics
Affected Vendors & Products
References
| Link | Providers |
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| https://fluentbit.io/announcements/v4.1.0/ |
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History
Wed, 26 Nov 2025 11:15:00 +0000
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Fluentbit
Fluentbit fluent Bit |
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Fluentbit
Fluentbit fluent Bit |
Mon, 24 Nov 2025 16:15:00 +0000
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| Metrics |
cvssV3_1
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Mon, 24 Nov 2025 14:45:00 +0000
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| 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. | |
| Title | CVE-2025-12978 | |
| References |
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Status: PUBLISHED
Assigner: certcc
Published: 2025-11-24T14:42:06.305Z
Updated: 2025-11-24T15:29:06.000Z
Reserved: 2025-11-10T18:57:32.141Z
Link: CVE-2025-12978
Updated: 2025-11-24T15:10:53.870Z
Status : Awaiting Analysis
Published: 2025-11-24T15:15:46.873
Modified: 2025-11-25T22:16:16.690
Link: CVE-2025-12978
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