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TI-2026-83432 Aliases CVE-2026-63341

Uncaught exception in Aedes MQTT broker lets remote clients crash it

Priority HIGH 72CWE-248Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-248.

Summary

Aedes is an MQTT broker from moscajs that is affected before 1.1.1. It does not bound MQTT topic depth or structural complexity, so an excessively deep topic causes an uncaught exception (CWE-248) that terminates the entire broker process. A remote attacker only needs to establish an MQTT session, authenticated or unauthenticated depending on the broker configuration.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

Aedes is an MQTT broker that can run on any stream server. Prior to 1.1.1, the MQTT broker does not bound topic depth or structural complexity before passing topics through `mqemitter` into `qlobber`. A `PUBLISH`, `SUBSCRIBE`, or registered `Will` message containing an excessively deep topic can reach `qlobber._split_words` in `lib/qlobber.js` and trigger an uncaught `too many words` exception. Calls from `handlers/subscribe.js` and the publishing logic are not protected against that exception, so it escapes to the `Node.js event loop` and terminates the entire broker. The `Will` path is independently reachable when a client disconnects ungracefully: it calls `broker.publish` directly and bypasses the `PUBLISH` handler. An attacker must be able to establish an `MQTT session`, authenticated or unauthenticated according to broker configuration. A successful attack disconnects all legitimate clients and prevents reconnection until the broker process restarts. This issue is fixed in version 1.1.1.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00365 30th percentileScored 2026-11-07
Fix Fixed aedes (moscajs): 1.1.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
moscajsaedesbefore 1.1.11.1.1Patch availableCNA
  • aedes Vendormoscajs Affected before 1.1.1 Fixed in 1.1.1 Patch available CNA

Remediation

Upgrade moscajs aedes to version 1.1.1.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

  • Fix · CNA aedes (moscajs) Fixed in 1.1.1

Timeline

  1. 2026-10-30 Threatist record created from CVE-2026-63341
  2. 2026-11-01 Priority changed: MEDIUM → LOW
  3. 2026-11-05 CISA SSVC decision points changed
  4. 2026-11-05 Priority changed: LOW → HIGH

References

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences