CVE-2026-85724
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.
What this means for your business
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 9.6 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N- Weakness
- CWE-155
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-09-23
- Last modified
- 2026-09-24
- Sources
- NVD