http4s has HTTP/2 Denial of Service with Ember Backend

Date Aug 26, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product Maven ยท org.http4s:http4s-ember-core_2.12
CVE CVE-2026-54556
High-risk advisory CVE-2026-54556

Summary

http4s has HTTP/2 Denial of Service with Ember Backend

Why it matters

GitHub has published a reviewed security advisory for org.http4s:http4s-ember-core_2.12. Prioritize it with other application dependency updates, especially because EPSS places it in the 22% percentile.

Operator check

Check whether org.http4s:http4s-ember-core_2.12 is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 8.2. EPSS probability: 0.3%; percentile: 22%.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.