# CVE-2026-128424: Kroxylicious-authorizer-acl: kroxylicious: acl rule file regex escapes are stripped, broadening 'matching' authorization rules

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

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.

## Remediation

- workaround: Until a fixed release is available, write regex escapes with doubled backslashes (for example `/orders\\.v1/`), audit existing `matching` rules for unintended matches, and prefer exact or `like` predicates where regex matching is not required. (source: CNA: redhat)

## Affected products and versions

- Red Hat / streams for Apache Kafka 3 (kroxylicious-authorizer-acl): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-863

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-128424 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2572937 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://github.com/kroxylicious/kroxylicious/issues/5236 (CNA: redhat)

- https://github.com/kroxylicious/kroxylicious/pull/5294 (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-128424; retrieved 2026-11-13; source updated 2026-11-13

Revision: 265c1e44bade90f2367f77261a3b8e4da89b9b5cb2230d223427638eb5e88e1b

Canonical: https://y2.dev/cve/CVE-2026-128424

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