CVE-2021-27186
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.99%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.99% probability · 80th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- treasuredata/fluent bit
- Source
- cve@mitre.org
EPSS 2.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/fluent/fluent-bit/issues/3044Exploit, Third Party Advisory
- https://github.com/fluent/fluent-bit/pull/3045Exploit, Patch, Third Party Advisory
- https://github.com/fluent/fluent-bit/pull/3047Patch, Third Party Advisory
- https://github.com/fluent/fluent-bit/issues/3044Exploit, Third Party Advisory
- https://github.com/fluent/fluent-bit/pull/3045Exploit, Patch, Third Party Advisory
- https://github.com/fluent/fluent-bit/pull/3047Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.