Client crash via unchecked PUBLISH topic length
Published Jun 14, 2026 · Updated Jun 14, 2026
Out-of-bounds read in Liam Bindle MQTT-C 1.1.6 and earlier allows remote attackers to crash subscribed clients via a crafted PUBLISH packet. The mqtt_unpack_publish_response() parser trusts topic_name_size, advances beyond remaining_length, and underflows application_message_size before memmove(). Exploitation requires control of the broker or traffic injection into an unencrypted session; the resulting read crashes the client and can disclose adjacent heap memory.
Summary
What happened
Out-of-bounds read in Liam Bindle MQTT-C 1.1.6 and earlier allows remote attackers to crash subscribed clients via a crafted PUBLISH packet. The mqtt_unpack_publish_response() parser trusts topic_name_size, advances beyond remaining_length, and underflows application_message_size before memmove(). Exploitation requires control of the broker or traffic injection into an unencrypted session; the resulting read crashes the client and can disclose adjacent heap memory.
The record
- CVE
- CVE-2026-54412
- Published
- Jun 14, 2026
- Updated
- Jun 14, 2026
- Vendor
- Liam Bindle
- Product
- MQTT-C
- Classifications
- CWE-191, CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 14, 2026CVE publishedPublication date reported by the CVE source.
- Jun 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=1.1.6
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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