CVE-2026-63448 Suricata smb: some SMB flows can cause resource exhaustion
Attackers can cause resource exhaustion in Suricata by sending sustained one-directional SMB traffic, leading to CPU and memory depletion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63448?
CVE-2026-63448 is a medium-severity denial of service vulnerability in Oisf Suricata, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-63448?
It affects 1 product.
Products include Oisf Suricata.
How do I fix CVE-2026-63448?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-63448 being exploited?
There is no known exploitation of CVE-2026-63448 in the wild and no public exploit code.
Other vulnerabilities in Oisf Suricata
Sources
Also known as DEBIAN-CVE-2026-63448, GHSA-hvvj-c8xx-9g35, UBUNTU-CVE-2026-63448.