# CVE-2026-44025 — fluent fluentd

> As of 2026-07-09, CVE-2026-44025 is a HIGH-severity vulnerability in fluent fluentd, CVSS v3.1 7.5, EPSS 0.4% (39.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-44025, most recently “Multiple Fluentd Vulnerabilities: RCE via Tag Placeholder (CVE-2026-44024), Info Disclosure (CVE-2026-44025), Decompression Bomb DoS (CVE-2026-44160), and SSRF (CVE-2026-44161)”.

**Last updated:** 2026-07-09

## What is CVE-2026-44025?

Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on. Prior to 1.19.3, Fluentd's Monitor Agent plugin in_monitor_agent exposes internal metrics and plugin information via a REST API, and responses from /api/plugins.json and related endpoints unintentionally include internal instance variables that may contain database passwords, API keys, or cloud credentials. This issue is fixed in version 1.19.3.

The record classifies CVE-2026-44025 under weakness class [CWE-306](https://intel.threadlinqs.com/cwe/CWE-306). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 107 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 39.0% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-08, last modified 2026-07-09

## Is CVE-2026-44025 being exploited?

It currently carries a trending score of 21 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [fluent](https://intel.threadlinqs.com/vendors/fluent): fluentd

Affected software packages:

- `rubygems:fluentd` — patched in 1.19.3

## How to fix CVE-2026-44025

The record marks a vendor fix as available for CVE-2026-44025. Fixed versions are recorded for 1 package: rubygems:fluentd 1.19.3. Patch reference: [https://github.com/fluent/fluentd/commit/990921518971699b9a97441970674d1800e29177](https://github.com/fluent/fluentd/commit/990921518971699b9a97441970674d1800e29177). Vendor advisory: [https://github.com/fluent/fluentd/security/advisories/GHSA-pr7j-96cj-549h](https://github.com/fluent/fluentd/security/advisories/GHSA-pr7j-96cj-549h). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-44025

1 tracked threat in the Threadlinqs corpus references CVE-2026-44025, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Fluentd Vulnerabilities: RCE via Tag Placeholder (CVE-2026-44024), Info Disclosure (CVE-2026-44025), Decompression Bomb DoS (CVE-2026-44160), and SSRF (CVE-2026-44161)](https://intel.threadlinqs.com/threat/TL-2026-1041) — HIGH · 2026-07-01

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/fluent/fluentd/security/advisories/GHSA-pr7j-96cj-549h)

**Other references**

- [github.com](https://github.com/fluent/fluentd/pull/5392)
- [github.com (990921518971699b9a97441970674d1800e29177)](https://github.com/fluent/fluentd/commit/990921518971699b9a97441970674d1800e29177)
- [github.com (v1.19)](https://github.com/fluent/fluentd/releases/tag/v1.19.3)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-44025
Full detection coverage and IOCs for threats exploiting CVE-2026-44025 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp