CVE-2021-46879

Name: CVE-2021-46879
Creator: NVD / NIST
Published: 2023-04-11T18:15:58.387+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.38%

Last modified Jun 17, 2026

CVE-2021-46879 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. An issue was discovered in Treasure Data Fluent Bit 1.7.1, a wrong variable is used to get the msgpack data resulting in a heap overflow in flb_msgpack_gelf_value_ext. An attacker can craft a malicious file and tick the victim to open the file with the software, triggering a heap overflow and execute arbitrary code on the target system.. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

Description

An issue was discovered in Treasure Data Fluent Bit 1.7.1, a wrong variable is used to get the msgpack data resulting in a heap overflow in flb_msgpack_gelf_value_ext. An attacker can craft a malicious file and tick the victim to open the file with the software, triggering a heap overflow and execute arbitrary code on the target system.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.38%

29.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Treasuredata	Fluent Bit	1.7.1

References

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26851Exploit, Issue Tracking, Patch, Third Party Advisory
https://github.com/fluent/fluent-bit/pull/3100Patch
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26851Exploit, Issue Tracking, Patch, Third Party Advisory
https://github.com/fluent/fluent-bit/pull/3100Patch

Timeline

Published: Apr 11, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-46879?

How severe is CVE-2021-46879?

CVE-2021-46879 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.

How do I fix CVE-2021-46879?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-46879?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST