CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-69213
High (7.5). EPSS 0.6% chance of exploitation in the next 30 days. Fixed in org.http4s:http4s-ember-core_2.12 0.23.35.
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.
Severity
- EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 50% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-400, CWE-770
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-8f3q-3jmv-7prw | Maven | org.http4s:http4s-ember-core_2.12 | <0.23.35 | 0.23.35 |
| GHSA-8f3q-3jmv-7prw | Maven | org.http4s:http4s-ember-core_2.13 | <0.23.35 | 0.23.35 |
| GHSA-8f3q-3jmv-7prw | Maven | org.http4s:http4s-ember-core_3 | <0.23.35 | 0.23.35 |
| GHSA-8f3q-3jmv-7prw | Maven | org.http4s:http4s-ember-core_3 | >=1.0.0-M1 <1.0.0-M47 | 1.0.0-M47 |
| GHSA-8f3q-3jmv-7prw | Maven | org.http4s:http4s-ember-core_2.13 | >=1.0.0-M1 <1.0.0-M47 | 1.0.0-M47 |