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Vulnerability record · CVE-2021-27186 · published 10 February 2021

CVE-2021-27186: Treasuredata fluent bit null pointer dereference vulnerability

Treasuredata · Fluent Bit

Fluent Bit 1.6.10 has a NULL pointer dereference when an flb_malloc return value is not validated by flb_avro.c or http_server/api/v1/metrics.c.

7.5 CVSS 3.1 High EPSS 2.0% · top 20.2% CWE-476 · NULL pointer dereference
7.5CVSS 3.1 base score, v2 5.0
2.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 4 tagged exploit
17 Jun 2026Last modified by NVD

Description

Fluent Bit 1.6.10 has a NULL pointer dereference when an flb_malloc return value is not validated by flb_avro.c or http_server/api/v1/metrics.c.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/fluent/fluent-bit/issues/3044 ExploitThird Party Advisory
https://github.com/fluent/fluent-bit/pull/3045 ExploitPatchThird Party Advisory
https://github.com/fluent/fluent-bit/pull/3047 PatchThird Party Advisory
https://github.com/fluent/fluent-bit/issues/3044 ExploitThird Party Advisory
https://github.com/fluent/fluent-bit/pull/3045 ExploitPatchThird Party Advisory
https://github.com/fluent/fluent-bit/pull/3047 PatchThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-27186), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.