Bug 2538875 (CVE-2026-57227)

Summary: CVE-2026-57227 suricata: Suricata: Denial of Service via unbounded MQTT message processing
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Suricata. The MQTT parser in Suricata permits repeated PUBREC or PUBREL messages to be appended to a transaction without a limit. A remote attacker can send crafted MQTT traffic to grow the transaction state indefinitely, consuming excessive CPU and memory resources. This can lead to a significant slowdown or a complete denial of service for the system.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2539183    
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Description OSIDB Bzimport 2026-09-22 21:01:37 UTC 
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 7.0.0 until 7.0.17 and 8.0.6, the MQTT parser in rust/src/mqtt/mqtt.rs permits repeated PUBREC or PUBREL messages to be appended to one transaction without a limit. Crafted MQTT traffic can grow transaction state indefinitely, consuming CPU and memory and causing slowdown or denial of service. This issue is fixed in versions 8.0.6 and 7.0.17.