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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-69202

Http4s Ember HTTP/2: unbounded inbound body buffering

Description

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s HTTP/2 flow-control window is replenished according to bytes received from the network rather than bytes consumed by the application, while each stream stores DATA in an unbounded channel. A hostile peer can therefore send a body faster than a slow or non-draining application consumes it, retaining payloads in heap on an ember-server or ember-client configured with withHttp2. The patch bounds the per-stream H2Connection body channel so application consumption applies backpressure. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

http4s http4s

  • < 0.23.35affected
  • >= 1.0.0-M1, < 1.0.0-M47affected

References