CVE-2024-50609: An issue was discovered in Fluent Bit 3.1.9

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2024-50609 is a high-severity flaw (CVSS 7.5) affecting fluent bit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in Fluent Bit 3.1.9. When the OpenTelemetry input plugin is running and listening on an IP address and port, one can send a packet with Content-Length: 0 and it crashes the server. Improper handling of the case when Content-Length is 0 allows a user (with access to the endpoint) to perform a remote Denial of service attack. The crash happens because of a NULL pointer dereference when 0 (from the Content-Length) is passed t

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-476
Published	2025-02-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: treasuredata

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-02-18 18:15 UTCPublished CVE record published
2026-06-17 08:04 UTCUpdated Record last modified

treasuredata fluent bit DOWNGRADE

Affected: 3.1.9

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.1.9

1. Check installed version

apt-cache policy fluent-bit || rpm -q fluent-bit || fluent-bit --version

2. No fixed release: DOWNGRADE to a release before 3.1.9 (Debian / Ubuntu)

apt-cache madison fluent-bit sudo apt install fluent-bit=<VERSION_BEFORE_3.1.9> sudo apt-mark hold fluent-bit

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list fluent-bit sudo dnf downgrade fluent-bit-<VERSION_BEFORE_3.1.9> sudo dnf versionlock add fluent-bit

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-50609?

fluent bit: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-50609 being exploited?

CVE-2024-50609 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-50609 affect?

CVE-2024-50609 affects fluent bit. Severity is high (CVSS 7.5). An issue was discovered in Fluent Bit 3.1.9. When the OpenTelemetry input plugin is running and listening on an IP address and port, one can send a packet with Content-Length: 0 and it crashes the server. Improper handling of the case when

How urgent is CVE-2024-50609?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

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CVE-2025-12969 MEDIUM 6.5 DOWNGRADE Fluent Bit in_forward input plugin does not properly enforce the security.users authentication mechanism under
CVE-2025-12972 MEDIUM 5.3 DOWNGRADE Fluent Bit out_file plugin does not properly sanitize tag values when deriving output file names
CVE-2025-12978 MEDIUM 5.4 DOWNGRADE Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins contain a flaw in the tag_key validation log

References

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