CVE-2025-12977

CVE-2025-12977

Published Nov 24, 2025 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins fail to sanitize tag_key inputs. An attacker with network access or the ability to write records into Splunk or Elasticsearch can supply tag_key values containing special characters such as newlines or ../ that are treated as valid tags. Because tags influence routing and some outputs derive filenames or contents from tags, this can allow newline injection, path traversal, forged record injection, or log misrouting, impacting data integrity and log routing.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Treasuredata
Treasuredata fluent Bit
CPEs cpe:2.3:a:treasuredata:fluent_bit:4.1.0:*:*:*:*:*:*:*
Vendors & Products Treasuredata
Treasuredata fluent Bit
Type Values Removed Values Added
First Time appeared Fluentbit
Fluentbit fluent Bit
Vendors & Products Fluentbit
Fluentbit fluent Bit
Type Values Removed Values Added
Weaknesses CWE-1287
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins fail to sanitize tag_key inputs. An attacker with network access or the ability to write records into Splunk or Elasticsearch can supply tag_key values containing special characters such as newlines or ../ that are treated as valid tags. Because tags influence routing and some outputs derive filenames or contents from tags, this can allow newline injection, path traversal, forged record injection, or log misrouting, impacting data integrity and log routing.
Title CVE-2025-12977
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
certcc
Published
Updated
Jan 7, 2026, 3:36 PM
Reserved
Nov 10, 2025, 6:57 PM
Status
Modified
Published
Nov 24, 2025, 3:15 PM
Modified
Oct 18, 2026, 8:10 PM