What’s Vulnerable › Vulnerabilities

CVE-2026-85724: Moquette pattern ACL wildcard injection allows cross-tenant authorization bypass

• Severity: critical (CVSS 9.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-09-23 · updated 2026-09-25
• Weakness: CWE-155

Description

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, when pattern-based ACL rules are configured, AuthorizationsCollector.canDoOperation substitutes client ID and username values directly into rules containing %c or %u and then treats the result as an MQTT topic filter. A client that uses + or # in either identity can broaden the substituted filter and gain cross-tenant read and write access. A # identity can also produce an invalid filter that triggers a NullPointerException in Topic.match and disrupts session processing. This issue is fixed in version 0.18.1.

Affected products

• moquette-io moquette: before 0.18.1 — fixed in 0.18.1

How to fix

Upgrade to a fixed version: moquette-io moquette 0.18.1. Check the vendor advisory for mitigations.

References

• https://github.com/moquette-io/moquette/commit/b4a98bb3f3425ece476ed073aa080c627c1239af
• https://github.com/moquette-io/moquette/releases/tag/v0.18.1
• https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq
• https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq

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