What is CVE-2026-63448?

CVE-2026-63448 is Suricata smb: some SMB flows can cause resource exhaustion. The supplied enrichment data classifies it as Denial of Service mapped to CWE-400 Uncontrolled Resource Consumption; CWE-401 CWE-401; CWE-407 CWE-407.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-63448. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-63448 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-63448. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-63448 using CVSS 5.9, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumDenial of Service

CVE-2026-63448

CVE-2026-63448 — Suricata smb: some SMB flows can cause resource exhaustion

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.

Published Sep 18, 2026Updated Sep 18, 2026Sources: NVD, OISF (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

OISF

2 products listed

CVSS base

5.9

medium

Remediation

The vendor's own words where we have them.

Upgrade suricata to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
OISF	suricata	>= 8.0.0, < 8.0.6	Vulnerable
OISF	suricata	< 7.0.17	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

None

Integrity

None

Scope

Unchanged

Attack Complexity

High

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
5.9	CVSS 3.1	medium	2.2	3.6	GitHub (CNA), OISF (CNA)

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-401 · Missing Release of Memory after Effective Lifetime

DoS: Crash, Exit, or Restart
DoS: Instability
DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)

Mitigation: Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone. For example, glibc in Linux provides protection against free of invalid pointers. When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391]. To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

CWE-407 · Inefficient Algorithmic Complexity

DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)
DoS: Resource Consumption (Other)

Weakness & attack patterns

CWE-400Uncontrolled Resource Consumption
CWE-401
CWE-407

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-147 · XML Ping of the DeathCAPEC-492 · Regular Expression Exponential BlowupCAPEC-197 · XML Entity Expansion

T1499Endpoint Denial of Service

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /src/smb.
Prioritize edge telemetry for network-reachable suricata.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 5.9 (AV:N)
Sep 18, 2026 · NVD
Initial · CVE published
Sep 18, 2026 · NVD
CVE published by MITRE.
Sep 18, 2026 · SOCRadar CTI

References

10 on the record

github.com/OISF/suricata/commit/755d6c3061de4d7ba97f0ed31cdc17ab8cab4476
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/commit/7ec9d72d28b9370712cf77a5b9d40d6b5db27cb4
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/commit/88adab8bd3d62912941647ab65032d5ec75c893a
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/commit/9a54a043516e644bb7b9d34117a91977f950a281
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/commit/bc39274a638d1cca2391cfa4891c8b6c255ff9ce
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/commit/c8f68b0e4f9e721dca1c9ed6e08597c6964c7ac3
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/releases/tag/suricata-7.0.17
Exploit, Third Party Advisory, Mitre
github.com/OISF/suricata/releases/tag/suricata-8.0.6
Exploit, Third Party Advisory, Mitre

Elsewhere on this site

OISFevery CVE for this vendor
Denial of Servicesame class
CWE-400other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-63448 is Suricata smb: some SMB flows can cause resource exhaustion, a medium vulnerability affecting suricata from OISF. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-63448. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-63448. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.9 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.