{"id":"CVE-2026-69203","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, An Ember server with HTTP/2 enabled through withHttp2 does not enforce SETTINGS_MAX_CONCURRENT_STREAMS for peer-created streams. One unauthenticated connectio…","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":"org.http4s:http4s-ember-core_2.12","affected":["org.http4s:http4s-ember-core_2.12 <= 0.23.34","org.http4s:http4s-ember-core_2.13 <= 0.23.34","org.http4s:http4s-ember-core_3 <= 0.23.34","org.http4s:http4s-ember-core_2.13 >= 1.0.0-M1, <= 1.0.0-M46","org.http4s:http4s-ember-core_3 >= 1.0.0-M1, <= 1.0.0-M46"],"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_2.13 1.0.0-M47","org.http4s:http4s-ember-core_3 1.0.0-M47"],"published":"2026-09-15","updated":"2026-09-16","sourceUpdated":"2026-09-16T20:38:04.943","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-69203","references":[{"url":"https://github.com/http4s/http4s/commit/4983de1f93f2caaa3b9de310cf6a9db32c50d66e","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-9vwc-pc8p-253q","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-9vwc-pc8p-253q"}],"tags":["nvd","ghsa","maven","cve.org"],"aliases":["GHSA-9vwc-pc8p-253q"],"ecosystem":"maven","ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-15T19:36:24.682974Z"},"ingestedAt":"2026-09-15T19:42:58.814Z","epss":0.0046,"epssPercentile":0.39179,"slug":"CVE-2026-69203","body":"## Overview\n\nHttp4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, An Ember server with HTTP/2 enabled through withHttp2 does not enforce SETTINGS_MAX_CONCURRENT_STREAMS for peer-created streams. One unauthenticated connection can open an unbounded number of streams, each retaining per-stream state until heap exhaustion. The same unchecked allocation is reachable in an ember-client through server-initiated PUSH_PROMISE frames because enablePush is not enforced. 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-2026-69203)\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_2.13 >= 1.0.0-M1, <= 1.0.0-M46`\n- `org.http4s:http4s-ember-core_3 >= 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_2.13 1.0.0-M47`\n- `org.http4s:http4s-ember-core_3 1.0.0-M47`\n\nSource: https://github.com/advisories/GHSA-9vwc-pc8p-253q","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}