Quick answers
- Is CVE-2026-36590 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-36590 being exploited in the wild.
- How severe is CVE-2026-36590?
- Informational severity, with a CVSS score of 7.5, published 15 July 2026.
- Which products and versions are affected?
- EMQ NanoMQ v0.24.9.
- Is there a fix for CVE-2026-36590?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-36590 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-36590?
- Check whether you run EMQ NanoMQ at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A resource exhaustion vulnerability exists in EMQ NanoMQ v0.24.9 due to a memory leak in the nni_qos_db_set function within the broker_tcp.c and mqtt_qos_db_api.c components. The flaw is triggered when processing certain MQTT packets, leading to unreleased memory allocations (CWE-772). A remote, unauthenticated attacker can exploit this by sending a sequence of crafted packets, eventually exhausting system RAM and causing a denial of service. While the NanoMQ team has disputed the issue as configuration-related, technical analysis and AddressSanitizer (ASAN) logs confirm the leak occurs during routine QoS database operations.
Affected products
- EMQ NanoMQ v0.24.9
Timeline
- 2026-06-17: disclosed: Initial public disclosure by researcher
- 2026-07-15: advisory: CVE published to NVD dataset