---
id: "CVE-2026-118952"
kind: "vulnerability"
aliases: ["CVE-2026-118952"]
title: "Kroxylicious: ACL prefix matching can let a Kafka client read denied topics"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["acl", "infrastructure", "kafka", "kroxylicious"]
not_affected_if: ["no-kafka-authenticated-clients", "no-kroxylicious", "no-prefix-acl-rules"]
published_at: "2026-10-30T07:16:33+00:00"
first_seen_at: "2026-10-30T07:29:00+00:00"
updated_at: "2026-10-30T07:30:08+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118952", "first_seen_at": "2026-10-30T07:29:00+00:00"}]
---

# Kroxylicious: ACL prefix matching can let a Kafka client read denied topics

Kroxylicious, a Kafka proxy, has a flaw in its ACL authorizer where overlapping prefix rules may be applied to the wrong principal or skipped. An authenticated Kafka client may therefore access a resource such as a topic that the ACL configuration should deny.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-10-30T07:29:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118952

## From the sources

A flaw was found in the Kroxylicious ACL authorizer. Its prefix-matching logic may apply a rule to a principal of a different type, or fail to check a broader matching rule when prefixes overlap. Depending on the ACL configuration, this may allow an authenticated Kafka client to access a resource (such as read a topic) that should be denied.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_