Improper handling of highly compressed data in Fluentd - #VU152735
Published: September 29, 2026
Vulnerability identifier: #VU152735
CSH Severity: Low
CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-409
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper handling of highly compressed data in the streaming decompression path of Buffer::Chunk#open and #write_to when flushing compressed buffer chunks to an output IO or backup chunk. A remote attacker can supply highly compressible data to cause a denial of service.
Buffer compression must be enabled.
Affected software
Fluentd
Remediation
Install security update from vendor's website.
Fluentd - update to 1.19.4