HIGH

CVE-2019-9749

CVSS v3

7.5

HIGH

EPSS Score

1.7 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2019-9749 yet.

Full record on NVD

Description

An issue was discovered in the MQTT input plugin in Fluent Bit through 1.0.4. When this plugin acts as an MQTT broker (server), it mishandles incoming network messages. After processing a crafted packet, the plugin's mqtt_packet_drop function (in /plugins/in_mqtt/mqtt_prot.c) executes the memmove() function with a negative size parameter. That leads to a crash of the whole Fluent Bit server via a SIGSEGV signal.

Technical details

Published: 2019-03-13

Frequently asked questions

What is CVE-2019-9749?

Is CVE-2019-9749 actively exploited?

Active exploitation of CVE-2019-9749 has not been confirmed. Its EPSS score was 1.7% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2019-9749?

CVE-2019-9749 has a CVSS v3 base score of 7.5 (HIGH severity).

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