---
id: "CVE-2026-128424"
page: "https://infrastack.ai/live/CVE-2026-128424"
kind: "vulnerability"
aliases: ["CVE-2026-128424"]
title: "Kroxylicious: ACL regex escapes lost, allow rules match extra Kafka resources"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["acl", "infrastructure", "kafka", "kroxylicious"]
not_affected_if: ["auth-required", "no-regex-acl-rules"]
published_at: "2026-11-13T07:17:20+00:00"
first_seen_at: "2026-11-13T07:45:52+00:00"
updated_at: "2026-11-13T07:47:12+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-128424", "first_seen_at": "2026-11-13T07:45:52+00:00"}]
exploit_sources: []
---

# Kroxylicious: ACL regex escapes lost, allow rules match extra Kafka resources

Link for people: https://infrastack.ai/live/CVE-2026-128424 (this .md is for agents)

Kroxylicious, a Kafka proxy, drops backslash escapes from regex literals in its ACL rules file. An allow rule such as matching /orders\.v1/ then also matches names like ordersXv1, so an authenticated Kafka client can reach topics it should be denied.

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

## Timeline

- 2026-11-13T07:45:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-128424

## From the sources

A flaw was found in Kroxylicious. The ACL authorizer's rules-file parser unquotes `matching /…/` regular-expression literals using the string unquoting rules, which strips every backslash escape. As a result, an allow rule such as `matching /orders\.v1/` is compiled as the regex `orders.v1`, which also matches unintended names such as `ordersXv1`, and character classes such as `\d` and `\w` lose their special meaning. Allow rules written with regex escapes can therefore apply to more resources than the author intended. Depending on the ACL configuration, this may allow an authenticated Kafka client to access a resource (such as read or write a topic) that should have been denied.

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