CVE-2022-39379Public exploitNetwork attack vector

Remote code execution via Oj object deserialization

Published Nov 2, 2022 · Updated Apr 23, 2025

Insecure deserialization in Fluentd 1.13.2 through 1.15.2 allows remote attackers to execute arbitrary code via crafted JSON. Fluentd passes JSON to Oj.load in object mode, which instantiates attacker-selected Ruby objects and permits a gadget chain to invoke commands. Exploitation requires Oj to be installed, FLUENT_OJ_OPTION_MODE to equal object, and an input configured to parse JSON; default setups are unaffected.

CVSS severity9.8
Critical
EPSS probability44.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure deserialization in Fluentd 1.13.2 through 1.15.2 allows remote attackers to execute arbitrary code via crafted JSON. Fluentd passes JSON to Oj.load in object mode, which instantiates attacker-selected Ruby objects and permits a gadget chain to invoke commands. Exploitation requires Oj to be installed, FLUENT_OJ_OPTION_MODE to equal object, and an input configured to parse JSON; default setups are unaffected.

The record

CVE
CVE-2022-39379
Published
Nov 2, 2022
Updated
Apr 23, 2025
Vendor
Fluentd
Product
Fluentd
Classifications
CWE-502, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 2, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.13.2, < 1.15.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Fluentd · Fluentdversion=>= 1.13.2, < 1.15.3

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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