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No exploitation reportedFix available

CVE-2021-36088

No exploitation reported by the sources we read.

  • Published2021-07-01
  • Fixed in1.7.5
  • WeaknessCWE-415

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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).

Timeline

dates in UTC
  1. 2021-07-0103:15CVE publishedNVD

Versions per branch

OSV · NVD · CISA-ADP
fluent-bit
BranchAffectedFixed in
1.7≥ 1.7.0, < 1.7.51.7.5
Treasuredata fluent bit
BranchAffectedFixed in
1.7≥ 1.7.0, ≤ 1.7.4no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update fluent-bit to 1.7.5

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2021-07-01
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-89w3-2j93-4g79

Frequently asked questions

What is CVE-2021-36088?

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).

Is CVE-2021-36088 actively exploited?

Active exploitation of CVE-2021-36088 has not been confirmed. Its EPSS score was 2.4% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-36088?

CVE-2021-36088 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record