CVE-2026-69202Http4s Ember HTTP/2: unbounded inbound body buffering
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-400, CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Deferred
- Record last updated
- Sep 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
http4s http4s http4s:http4s (from the name) | before 0.23.35; from 1.0.0-M1, < 1.0.0-M47 | CNA record |
References
- https://github.com/http4s/http4s/security/advisories/GHSA-6m4x-pp6q-5jmmx-refsource-confirm
- https://github.com/http4s/http4s/commit/22d2335975d02dc9fb9fb75cfe002279521d86acx-refsource-misc
- https://github.com/http4s/http4s/releases/tag/v0.23.35x-refsource-misc
- https://github.com/http4s/http4s/releases/tag/v1.0.0-M47x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.