CVE WatchSep 18, 2026

CVE-2026-63448

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.

CVSS

5.9

Medium

EPSS

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KEV

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Exploit Today

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0-100

Published: Sep 18, 2026 · Last modified: Sep 18, 2026 · CWE-400 · CWE-401 · CWE-407

EPSS · 30d

Not enough EPSS history yet.

Technical description

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.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-714187.5 HIG

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———Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, DNS-over-HTTP/2 processing in rust/src/http2/http2.rs retains previously processed HTTP/2 DATA frame contents instead of clearing the internal buffer. Multiple DATA frames with the EndOfStream flag set can grow the buffer to its 65 KiB limit while causing all prior contents to be processed again, producing quadratic CPU complexity, degraded packet processing, loss of monitoring visibility, or denial of service. This issue is fixed in version 8.0.6.8h CVE-2026-634527.5 HIG

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———Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, the HTTP/1 parser limits decompression work per transaction but does not limit how many small brotli compression bombs a single flow can submit. With response-body-decompress-layer-limit enabled, repeated compressed responses make the decompression paths in rust/htp perform expensive work for every transaction, degrading packet processing and potentially causing loss of monitoring visibility or denial of service. This issue is fixed in version 8.0.6.8h CVE-2026-634477.5 HIG

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———Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.5 until 8.0.6, the FTP parser in src/app-layer-ftp.c can continue allocating transactions after app-layer.protocols.ftp.max-tx is reached while processing one large chunk of FTP command data. The oversized transaction list is repeatedly processed with quadratic complexity after the too_many_transactions event, allowing crafted FTP traffic to degrade packet processing, reduce monitoring visibility, or cause denial of service. This issue is fixed in version 8.0.6.8h CVE-2026-634467.5 HIG

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———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 8.0.6.8h CVE-2026-572277.5 HIG

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———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 7.0.17.8h CVE-2026-572246.5 MED

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———Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, the DHCP parser in rust/src/dhcp/dhcp.rs creates stateless transactions without recording their packet direction with AppLayerTxData::for_direction(), so a sensor that observes only one direction cannot mark the unseen direction inspected or free completed transactions. The RDP parser in rust/src/rdp/rdp.rs has the same direction-state defect. The per-flow transaction list can grow without bound and cleanup repeatedly scans it, causing increasing CPU and memory consumption and eventual denial of service. This issue is fixed in version 8.0.6.8h