{"id":"CVE-2026-69213","title":"Http4s is a Scala interface for HTTP services","summary":"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 c…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-400","CWE-770"],"vendor":"http4s","product":"http4s","affected":["http4s < 0.23.35","http4s >= 1.0.0-M1, < 1.0.0-M47"],"patched":["org.http4s:http4s-ember-core_2.12 0.23.35","org.http4s:http4s-ember-core_2.13 0.23.35","org.http4s:http4s-ember-core_3 0.23.35","org.http4s:http4s-ember-core_3 1.0.0-M47","org.http4s:http4s-ember-core_2.13 1.0.0-M47"],"published":"2026-09-15","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:16:46.607","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-69213","references":[{"url":"https://github.com/http4s/http4s/commit/13fe24d6440bde2f1eb70121486cf59c278e6bae","label":"security-advisories@github.com"},{"url":"https://github.com/http4s/http4s/releases/tag/v0.23.35","label":"security-advisories@github.com"},{"url":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47","label":"security-advisories@github.com"},{"url":"https://github.com/http4s/http4s/security/advisories/GHSA-8f3q-3jmv-7prw","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-8f3q-3jmv-7prw"}],"tags":["nvd","cve.org","ghsa","maven"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-17T16:42:58.154505Z"},"epss":0.00361,"epssPercentile":0.29823,"aliases":["GHSA-8f3q-3jmv-7prw"],"ecosystem":"maven","ingestedAt":"2026-09-15T19:42:58.804Z","slug":"CVE-2026-69213","body":"## Overview\n\nHttp4s 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-69213)\n\nAffected packages:\n\n- `org.http4s:http4s-ember-core_2.12 <= 0.23.34`\n- `org.http4s:http4s-ember-core_2.13 <= 0.23.34`\n- `org.http4s:http4s-ember-core_3 <= 0.23.34`\n- `org.http4s:http4s-ember-core_3 >= 1.0.0-M1, <= 1.0.0-M46`\n- `org.http4s:http4s-ember-core_2.13 >= 1.0.0-M1, <= 1.0.0-M46`\n\nPatched in:\n\n- `org.http4s:http4s-ember-core_2.12 0.23.35`\n- `org.http4s:http4s-ember-core_2.13 0.23.35`\n- `org.http4s:http4s-ember-core_3 0.23.35`\n- `org.http4s:http4s-ember-core_3 1.0.0-M47`\n- `org.http4s:http4s-ember-core_2.13 1.0.0-M47`\n\nSource: https://github.com/advisories/GHSA-8f3q-3jmv-7prw","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}