CVE-2026-44161 json
Fluentd: Server-Side Request Forgery (SSRF) via Placeholder Expansion in `out_http`
published 2026-06-26 4 mo ago modified 2026-10-25 14 d ago also BIT-fluentd-2026-44161 , EUVD-2026-42439 , GHSA-72f5-rr8c-r6gr
- cvss
- 7.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 38%
- public exploits
- 0
- none known
Summary
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, the Fluentd out_http output plugin allows placeholders such as ${tag} in the endpoint configuration parameter, and if a placeholder value is derived from untrusted input an attacker can control the destination hostname of outbound HTTP requests and force requests to arbitrary internal services. This issue is fixed in version 1.19.3.
Patch / fix
- rubygems fluentd 1.19.3
- bitnami fluentd 1.19.3
- fluentd fluentd 1.19.3
- github.com/fluent/fluentd@c6a01ea commit
- github.com/fluent/fluentd#5394 pull request
- github.com/fluent/fluentd/releases/tag/v1.19.3 release
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:L |
| GitHub | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:L |
| OSV | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| rubygems | fluentd | <1.19.3 |
1.19.3 |
| bitnami | fluentd | <1.19.3 |
1.19.3 |
Affected products
- fluent fluentd
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
-
github.com
/fluent/fluentd/pull/5394
issue-tracking, patch
-
github.com
/fluent/fluentd/commit/c6a01ea2e0ea01977f8d615f7c6dbfae4cba88c9
patch
-
github.com
/fluent/fluentd/security/advisories/GHSA-72f5-rr8c-r6gr
web, mitigation, vendor-advisory, advisory
-
github.com
/fluent/fluentd/releases/tag/v1.19.3
web, product, release-notes, article
-
github.com
/fluent/fluentd
package
-
nvd.nist.gov
/vuln/detail/CVE-2026-44161
web
Sources
- CVE List CVE-2026-44161
- GitHub Advisory GHSA-72f5-rr8c-r6gr
- NVD CVE-2026-44161
- OSV BIT-fluentd-2026-44161
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.