CVE-2026-63446 Suricata app-layer: passed flows can retain transactions, causing resource exhaustion
Attackers can cause resource exhaustion in Suricata by triggering a logic error that prevents transaction cleanup on passed flows.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63446?
CVE-2026-63446 is a high-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. 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.
Which versions are affected by CVE-2026-63446?
It affects 1 product.
Products include Oisf Suricata.
How do I fix CVE-2026-63446?
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-2026-63446 being exploited?
There is no known exploitation of CVE-2026-63446 in the wild and no public exploit code.
Other vulnerabilities in Oisf Suricata
Sources
Also known as DEBIAN-CVE-2026-63446, GHSA-gjwr-75gq-877m, UBUNTU-CVE-2026-63446.