CVE-2026-69202
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 t
CVSS
7.5
High
EPSS
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KEV
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Exploit Today
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0-100
Published: Sep 15, 2026 · Last modified: Sep 15, 2026 · CWE-400 · CWE-770
Not enough EPSS history yet.
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.
- github.comhttps://github.com/http4s/http4s/commit/22d2335975d02dc9fb9fb75cfe002279521d86ac
- github.comhttps://github.com/http4s/http4s/releases/tag/v0.23.35
- github.comhttps://github.com/http4s/http4s/releases/tag/v1.0.0-M47
- github.comhttps://github.com/http4s/http4s/security/advisories/GHSA-6m4x-pp6q-5jmm