CVE-2026-33558: Information exposure vulnerability has been identified in Apache Kafka. The NetworkClient component will outp

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MEDIUM 5.3REMOTEWATCHLISTUPGRADE

CVE-2026-33558 is a medium-severity flaw (CVSS 5.3) affecting kafka. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Information exposure vulnerability has been identified in Apache Kafka. The NetworkClient component will output entire requests and responses information in the DEBUG log level in the logs. By default, the log level is set to INFO level. If the DEBUG level is enabled, the sensitive information will be exposed via the requests and responses output log. The entire lists of impacted requests and responses are: * AlterConfigsRequest * Alter

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-533
Published	2026-04-20
Last modified	2026-10-26

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-20 14:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

apache kafka UPGRADE

Affected: >= 0.11.0.0 and < 3.9.2 · 4.0.0 · 4.0.0 rc0 · 4.0.0 rc1 · 4.0.0 rc3

Fixed in: 3.9.2

Safe to downgrade to: a release before 0.11.0.0

1. Check installed version

apt-cache policy kafka || rpm -q kafka || kafka --version

2. UPGRADE to 3.9.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kafka

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kafka

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.11.0.0 (Debian / Ubuntu)

apt-cache madison kafka sudo apt install kafka=<VERSION_BEFORE_0.11.0.0> sudo apt-mark hold kafka

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list kafka sudo dnf downgrade kafka-<VERSION_BEFORE_0.11.0.0> sudo dnf versionlock add kafka

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-2026-33558?

kafka: upgrade to 3.9.2. Exact commands for each OS are on this page.

Is CVE-2026-33558 being exploited?

CVE-2026-33558 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-2026-33558 affect?

CVE-2026-33558 affects kafka. Severity is medium (CVSS 5.3). Information exposure vulnerability has been identified in Apache Kafka. The NetworkClient component will output entire requests and responses information in the DEBUG log level in the logs. By default, the log level is set to INFO level. I

How urgent is CVE-2026-33558?

Priority 41/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache Kafka vulnerabilities

Related CVEs

CVE-2026-33557 CRITICAL 9.1 UPGRADE A possible security vulnerability has been identified in Apache Kafka. By default, the broker property `sasl.
CVE-2026-35554 HIGH 8.7 UPGRADE A race condition in the Apache Kafka Java producer client’s buffer pool management can cause messages to be si

References

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