CVE-2022-39379: Fluentd vulnerable to remote code execution due to insecure deserialization (in non-default configuration)
Vulnerability summary
CVE-2022-39379 is a critical (CVSS 9.8) Deserialization of Untrusted Data vulnerability in fedoraproject fedora. EPSS estimates a 44.98% chance of exploitation in the next 30 days, higher than 98.7% of scored vulnerabilities.
Not severe (CVSS 3.1, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 02-11-2022PublishedVulnerability first disclosed.
- 23-04-2025Last modifiedVulnerability information updated.
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`.
CVSS metrics
3 scores · 3 sources · 1 version- CVE.orgCNA3.1LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:NDiffers
- OSV · RubygemsEcosystem advisory · calculated3.1LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:NDiffers
EPSS trend
Probability
44.98%
Chance of exploitation in the next 30 days
Percentile
99%
Versus all other CVEs
30-day change
No change 0.00 pp
From 44.98% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Fedoraproject1 product
- fedoraEOL37
Fluent1 product
- fluentd≥ 1.13.2, < 1.15.3
Fluentd1 product
- fluentd≥ 1.13.2, < 1.15.3
RubyGems1 product
- fluentd≥ 1.13.2, < 1.15.3
4 vendors · 4 products
References
7 links- github.com/fluent/fluentd/commit/48e5b85dab1b6d4c273090d538fc11b3f2fd8135WEBPatchThird Party Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- github.com/fluent/fluentdPACKAGE