Executive brief
Suricata is a network intrusion detection and prevention system used to monitor and protect network traffic. Versions 8.0.0 through 8.0.5 have a flaw in DNS-over-HTTP/2 processing that allows attackers to cause excessive CPU consumption and degrade monitoring visibility by sending specially crafted HTTP/2 frames, potentially leading to service disruption or denial of service.
Technical details
DNS-over-HTTP/2 processing in rust/src/http2/http2.rs fails to clear internal buffers after processing HTTP/2 DATA frames, allowing multiple frames with the EndOfStream flag to grow the 65 KiB buffer while reprocessing all prior contents, resulting in quadratic CPU complexity. The vulnerability requires network access to send malicious HTTP/2 frames and is fixed by clearing the data buffer after processing each frame.
Affected products
- OISF Suricata 8.0.0 through 8.0.5
Timeline
- 2026-09-18: disclosed
- 2026-09-18: patched: Fixed in version 8.0.6