TI-2021-14538 Aliases CVE-2021-36088 GHSA-89w3-2j93-4g79

Fluent Bit (aka fluent-bit) 1.7.0 through 1.7.4 has a double free in flb_free (called…

MEDIUM 53CWE-415Published 2021-07-01 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-415 and the CVSS impact.

Summary

Fluent Bit (aka fluent-bit) 1.7.0 through 1.7.4 has a double free in flb_free (called from flb_parser_json_do and flb_parser_do).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.02384 84th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:treasuredata:fluent_bit::::::::	1.7.0 – 1.7.4	Vulnerable	FluentBit

cpe:2.3:a:treasuredata:fluent_bit:*:*:*:*:*:*:*:* Versions 1.7.0 – 1.7.4 Vulnerable ·FluentBit

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2021-36088
2026-10-03 Alias added: GHSA-89w3-2j93-4g79

References

Exploit 1

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33750

Patch 2

Advisory 1

https://github.com/google/oss-fuzz-vulns/blob/main/vulns/fluent-bit/OSV-2021-702.yaml

TI-2024-17419 fluent-bit 2.2.2 contains a Use-After-Free vulnerability in /fluent-bit/plugins/custom_calyptia/calyptia.c. CVSS 3.1HIGH 7.5
TI-2024-15728 In Fluent Bit 2.1.8 through 2.2.1, a NULL pointer dereference can be caused via an… CVSS 3.1HIGH 7.5
TI-2024-04026 Fluent Bit Memory Corruption Vulnerability CVSS 3.1CRITICAL 9.8
TI-2021-21547 An issue was discovered in Treasure Data Fluent Bit 1.7.1, a wrong variable is used to… CVSS 3.1HIGH 7.8
TI-2021-21546 An issue was discovered in Treasure Data Fluent Bit 1.7.1, erroneous parsing in… CVSS 3.1HIGH 7.8
TI-2025-21098 An issue in fluent-bit v.3.7.2 allows a local attacker to cause a denial of service via… CVSS 3.1MEDIUM 5.5

See all 17 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences