What’s Vulnerable › Vulnerabilities

CVE-2026-71418: Suricata doh2: crafted HTTP/2 DATA frames can cause quadratic CPU consumption

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-18 · updated 2026-09-28
• Weakness: CWE-407

Description

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.

Affected products

• OISF suricata: from 8.0.0 before 8.0.6 — fixed in 8.0.6

How to fix

Upgrade to a fixed version: OISF suricata 8.0.6. Check the vendor advisory for mitigations.

References

• https://github.com/OISF/suricata/commit/1731805967edf5d31448db2ae43cf72c6cf46c11
• https://github.com/OISF/suricata/commit/26c26dea84f00de95151a0e16d21c1fcafac9648
• https://github.com/OISF/suricata/releases/tag/suricata-8.0.6
• https://github.com/OISF/suricata/security/advisories/GHSA-xjgq-3qw4-jp5f
• https://redmine.openinfosecfoundation.org/issues/8725

Get alerted when CVE-2026-71418 or the next vulnerability affects your stack