What’s Vulnerable › Vulnerabilities

CVE-2022-39379: Fluentd vulnerable to remote code execution due to insecure deserialization (in non-default configuration)

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 45.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-11-02 · updated 2026-06-17
• Weakness: CWE-502

Description

Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on. A remote code execution (RCE) vulnerability in non-default configurations of Fluentd allows unauthenticated attackers to execute arbitrary code via specially crafted JSON payloads. Fluentd setups are only affected if the environment variable `FLUENT_OJ_OPTION_MODE` is explicitly set to `object`. Please note: The option FLUENT_OJ_OPTION_MODE was introduced in Fluentd version 1.13.2. Earlier versions of Fluentd are not affected by this vulnerability. This issue was patched in version 1.15.3. As a workaround do not use `FLUENT_OJ_OPTION_MODE=object`.

Affected products

• Fedoraproject Fedora: 37
• fluentd: from 1.13.2 before 1.15.3 — fixed in 1.15.3

How to fix

Upgrade to a fixed version: fluentd 1.15.3. Check the vendor advisory for mitigations.

References

• https://github.com/fluent/fluentd/commit/48e5b85dab1b6d4c273090d538fc11b3f2fd8135
• https://github.com/fluent/fluentd/security/advisories/GHSA-fppq-mj76-fpj2
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MYD5QV66OLDHES6IKVYYM3Y3YID3VVCO/
• https://github.com/fluent/fluentd/commit/48e5b85dab1b6d4c273090d538fc11b3f2fd8135
• https://github.com/fluent/fluentd/security/advisories/GHSA-fppq-mj76-fpj2
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MYD5QV66OLDHES6IKVYYM3Y3YID3VVCO/

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