CVE-2026-54556: http4s has HTTP/2 Denial of Service with Ember Backend
http4s 0.23.x and 1.0 servers running ember with http2 enabled are vulnerable to a denial of service attack using a HPACK bomb vulnerability recently disclosed as affecting other http2 servers.
References
- github.com/advisories/GHSA-vmm3-xgcx-67hm
- github.com/http4s/http4s/commit/6e8eccd64a6a74ab4811897881e95e0e1b3a818e
- github.com/http4s/http4s/releases/tag/v0.23.35
- github.com/http4s/http4s/releases/tag/v1.0.0-M47
- github.com/http4s/http4s/security/advisories/GHSA-vmm3-xgcx-67hm
- nvd.nist.gov/vuln/detail/CVE-2026-54556
Code Behaviors & Features
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