VDB-403645 · CVE-2026-44162 · GCVE-0-2026-44162

fluent fluent-plugin-s3 up to 1.8.4 In S3 Input Plugin memory allocation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.4	$0-$5k	0.67-

Summaryinfo

A vulnerability marked as problematic has been reported in fluent fluent-plugin-s3 up to 1.8.4. Affected by this vulnerability is an unknown functionality of the component In S3 Input Plugin. This manipulation causes memory allocation. This vulnerability is registered as CVE-2026-44162. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in fluent fluent-plugin-s3 up to 1.8.4 and classified as problematic. Affected by this vulnerability is an unknown code of the component In S3 Input Plugin. The manipulation with an unknown input leads to a memory allocation vulnerability. The CWE definition for the vulnerability is CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. As an impact it is known to affect availability. The summary by CVE is:

fluent-plugin-s3 is an Amazon S3 input and output plugin for Fluentd. From 0.7.0 to 1.8.4, the in_s3 input plugin reads the entire decompressed payload of gzip, lzma2, and lzop objects into memory without enforcing a decompression_size_limit. An attacker with permission to upload objects to the monitored S3 bucket can provide a highly compressed object that expands excessively when Fluentd processes it. The resulting memory exhaustion can cause the operating system to terminate the Fluentd process and disrupt all log collection on the affected node. This issue is fixed in version 1.8.5.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-44162 since 05/05/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available.

Upgrading to version 1.8.5 eliminates this vulnerability.

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Productinfo

Vendor

fluent

Name

fluent-plugin-s3

Version

Website

Product: https://github.com/fluent/fluent-plugin-s3/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 2.7
CNA Vector (GitHub_M): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory allocation
CWE: CWE-789 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: fluent-plugin-s3 1.8.5

Timelineinfo

05/05/2026 CVE reserved
09/14/2026 +132 days Advisory disclosed
09/14/2026 +0 days VulDB entry created
09/14/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-44162 (🔒)
GCVE (CVE): GCVE-0-2026-44162
GCVE (VulDB): GCVE-100-403645

Entryinfo

Created: 09/14/2026 20:04
Changes: 09/14/2026 20:04 (64)
Complete: 🔍
Cache ID: 216::103