cvedb.io
CVE-2026-35217
MEDIUM · CVSS 6.5
EPSS exploitation probability: 0%
Published 2026-07-20T17:17:06.980 · Last modified 2026-07-20T19:17:21.643

Summary

NanoMQ contains a protocol-semantics flaw in its MQTT v5 `SUBSCRIBE` handling: if a subscription entry is missing the final 1-byte `Subscription Options` field, the broker may still accept the malformed packet and install the subscription into internal broker state. Under a specific packet-length construction, the same parser flaw also causes a 1-byte out-of-bounds read that crosses the real heap allocation boundary and is detected by ASAN as a `heap-buffer-overflow`. If the consumed byte happens to look acceptable, NanoMQ may continue and append the malformed subscription entry into its internal `subinfol` state. In that case, a `SUBSCRIBE` packet that should be rejected by MQTT rules is instead treated as a successful subscription. Whether ASAN reports the bug does not depend on MQTT's

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.