Bug 2538229 (CVE-2026-63448)

Summary: CVE-2026-63448 suricata: Suricata: Denial of Service due to SMB resource exhaustion
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Suricata, a network Intrusion Detection System (IDS), Intrusion Prevention System (IPS), and Network Security Monitoring (NSM) engine. A remote attacker can exploit this vulnerability by sending sustained one-directional Server Message Block (SMB) traffic. This causes the SMB parser to retain force-completed transactions, leading to an unbounded per-flow state. Consequently, this can result in CPU and memory exhaustion, causing a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2539194    
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Description OSIDB Bzimport 2026-09-22 17:27:57 UTC 
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6, the SMB parser can retain force-completed transactions on flows where Suricata sees payload in only one direction, including async-oneside flows, because cleanup waits for inspection in the unseen direction. The transaction creation paths in rust/src/smb can exceed the intended SMB_MAX_TX bound, and cleanup repeatedly scans the growing list. Sustained one-directional SMB traffic can therefore cause unbounded per-flow state and CPU and memory exhaustion. This issue is fixed in versions 8.0.6 and 7.0.17.