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HIGH severity

CVE-2024-27309 — kafka-metadata

HIGHFix: apache/kafka@c000b1f

CVE-2024-27309 is a high-severity (CVSS 7.4) CWE-863 vulnerability in org.apache.kafka:kafka-metadata. A fix is available for org.apache.kafka:kafka-metadata — see the affected versions and patch details below.

Apache Kafka: Potential incorrect access control during migration from ZK mode to KRaft mode

Also known asBIT-kafka-2024-27309GHSA-79vv-vp32-gpp7
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-27309.

EPSS Exploitation Probability

via FIRST.org ↗
1.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs67th percentile — riskier than 67% of all scored CVEsHighest risk
0.00%0.54%1.08%1.63%0.4%1.1%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
☕org.apache.kafka:kafka-metadata

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

While an Apache Kafka cluster is being migrated from ZooKeeper mode to KRaft mode, in some cases ACLs will not be correctly enforced.

Two preconditions are needed to trigger the bug:

  1. The administrator decides to remove an ACL
  2. The resource associated with the removed ACL continues to have two or more other ACLs associated with it after the removal.

When those two preconditions are met, Kafka will treat the resource as if it had only one ACL associated with it after the removal, rather than the two or more that would be correct.

The incorrect condition is cleared by removing all brokers in ZK mode, or by adding a new ACL to the affected resource. Once the migration is completed, there is no metadata loss (the ACLs all remain).

The full impact depends on the ACLs in use. If only ALLOW ACLs were configured during the migration, the impact would be limited to availability impact. if DENY ACLs were configured, the impact could include confidentiality and integrity impact depending on the ACLs configured, as the DENY ACLs might be ignored due to this vulnerability during the migration period.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenorg.apache.kafka:kafka-metadata≥ 3.5.0&&< 3.6.23.6.2org.apache.kafka:kafka-metadata:3.6.2

Affected Products

1 product · 1 configurations
Application
kafkaapache
≥ 3.5.0 && ≤ 3.6.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.kafka:kafka-metadata, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update org.apache.kafka:kafka-metadata to 3.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27309 is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

The vulnerability in Apache Kafka during the migration from ZooKeeper (ZK) to KRaft mode is of Moderate severity due to its potential impact on access control enforcement. By incorrectly interpreting the number of ACLs associated with a resource after an ACL removal, Kafka may misapply access permissions during the…

Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for CVE-2024-27309 (CC BY 4.0)

Frequently Asked Questions

While an Apache Kafka cluster is being migrated from ZooKeeper mode to KRaft mode, in some cases ACLs will not be correctly enforced. Two preconditions are needed to trigger the bug: 1. The administrator decides to remove an ACL 2. The resource associated with the removed ACL continues to have two or more other ACLs associated with it after the removal. When those two preconditions are met, Kafka will treat the resource as if it had only one ACL associated with it after the removal, rather than the two or more that would be correct. The incorrect condition is cleared by removing all brokers
O3 Security · Impact-Aware SCA

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CVE-2024-27309: kafka-metadata — Fixed in 3.6.2