Vulnerability Description
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember HTTP/2 serializes outbound frames through one unbounded queue consumed by writeLoop. When the peer stops reading, an unauthenticated HTTP/2 client can continue sending PING, SETTINGS, or DATA frames that cause Ember to enqueue acknowledgments or WINDOW_UPDATE frames faster than the writer drains them, exhausting heap memory on a server built with withHttp2. The shared behavior also affects an ember-client connected to a hostile HTTP/2 server, and the patch replaces the unbounded path with bounded, backpressured outbound queues. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/http4s/http4s/commit/13fe24d6440bde2f1eb70121486cf59c278e6bae
- https://github.com/http4s/http4s/releases/tag/v0.23.35
- https://github.com/http4s/http4s/releases/tag/v1.0.0-M47
- https://github.com/http4s/http4s/security/advisories/GHSA-8f3q-3jmv-7prw
FAQ
What is CVE-2026-69213?
CVE-2026-69213 is a vulnerability with a CVSS score of 7.5 (HIGH). Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember HTTP/2 serializes outbound frames through one unbounded queue consumed by writeLoop. When the peer stops reading, a...
How severe is CVE-2026-69213?
CVE-2026-69213 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-69213?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.