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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache Kafka | 3.5.0 – ≤ 3.5.2, 3.6.0 – ≤ 3.6.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | kafka | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.apache.kafka:kafka-metadata | >= 3.5.0, < 3.6.2 | 3.6.2 | GHSA-79vv-vp32-gpp7 |
Advisories 4
- WID-SEC-2025-0135 Oracle Communications Applications: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 3, 2026
- WID-SEC-2025-1564 Oracle Siebel CRM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jul 15, 2025
- NCSC-2025-0021 Kwetsbaarheden verholpen in Oracle Communications NCSC-NL (Netherlands) · Jan 22, 2025
- WID-SEC-2024-0857 Apache Kafka: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Sep 10, 2024