Bug 2538596 (CVE-2026-63446)

Summary: CVE-2026-63446 suricata: Suricata: Denial of Service via resource exhaustion in app-layer transaction handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
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 engine. Due to an inverted guard in the `AppLayerParserSetTransactionInspectId()` function, transactions on flows passed by a pass rule or exception policy are not correctly marked as inspected. This oversight prevents completed transactions from being freed, leading to their repeated rescanning. A remote attacker could exploit this by sending specially crafted network traffic, causing the per-flow list to grow indefinitely, resulting in CPU and memory exhaustion and a Denial of Service (DoS).
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Bug Depends On: 2539192    
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Description OSIDB Bzimport 2026-09-22 19:43:43 UTC 
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.