{"id":"CVE-2026-69213","aliases":["GHSA-8f3q-3jmv-7prw"],"url":"https://o3.security/vulnerability/CVE-2026-69213","summary":"Http4s Ember HTTP/2: unbounded outbound frame queue","details":"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.","published":"2026-09-15T19:08:21.856Z","modified":"2026-09-16T03:47:17.838429751Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.12","fixedVersion":"0.23.35"},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.13","fixedVersion":"0.23.35"},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_3","fixedVersion":"0.23.35"},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_3","fixedVersion":"1.0.0-M47"},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.13","fixedVersion":"1.0.0-M47"}],"fix":{"url":"https://github.com/http4s/http4s/commit/13fe24d6440bde2f1eb70121486cf59c278e6bae","label":"http4s/http4s@13fe24d"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69213.json"},{"type":"FIX","url":"https://github.com/http4s/http4s/commit/13fe24d6440bde2f1eb70121486cf59c278e6bae"},{"type":"WEB","url":"https://github.com/http4s/http4s/releases/tag/v0.23.35"},{"type":"WEB","url":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47"},{"type":"ADVISORY","url":"https://github.com/http4s/http4s/security/advisories/GHSA-8f3q-3jmv-7prw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-69213"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-16T03:47:17.838429751Z"}}