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Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M

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

High 7.5

In plain English

A high-severity security flaw in suricata from OISF. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 50.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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, 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13suricatano fix listedDEBIAN-CVE-2026-71418
Debian:14suricata1:8.0.6-1DEBIAN-CVE-2026-71418
Ubuntu:22.04:LTSsuricatano fix listedUBUNTU-CVE-2026-71418
Ubuntu:24.04:LTSsuricatano fix listedUBUNTU-CVE-2026-71418
Ubuntu:26.04:LTSsuricatano fix listedUBUNTU-CVE-2026-71418

Affected products (as reported)

VendorProductVersions
OISF suricata >= 8.0.0, < 8.0.6

Weakness: CWE-407 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References