{"cve":"CVE-2026-69203","nvd":{"published":"2026-09-15T20:17:39.120","modified":"2026-09-16T20:38:04.943","status":"Deferred","description":"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 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400","CWE-770"],"references":["https://github.com/http4s/http4s/commit/4983de1f93f2caaa3b9de310cf6a9db32c50d66e","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-9vwc-pc8p-253q"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:54:41.405518556+00:00"},"epss":{"cve":"CVE-2026-69203","score":0.0063,"percentile":0.50199,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-9vwc-pc8p-253q","url":"https://osv.dev/vulnerability/GHSA-9vwc-pc8p-253q","summary":"Http4s Ember HTTP/2 does not enforce SETTINGS_MAX_CONCURRENT_STREAMS","modified":"2026-09-15T20:00:40.544947819Z","packages":[{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.12","purl":"pkg:maven/org.http4s/http4s-ember-core_2.12","ranges":["<0.23.35"],"fixed":["0.23.35"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.13","purl":"pkg:maven/org.http4s/http4s-ember-core_2.13","ranges":["<0.23.35"],"fixed":["0.23.35"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_3","purl":"pkg:maven/org.http4s/http4s-ember-core_3","ranges":["<0.23.35"],"fixed":["0.23.35"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.13","purl":"pkg:maven/org.http4s/http4s-ember-core_2.13","ranges":[">=1.0.0-M1 <1.0.0-M47"],"fixed":["1.0.0-M47"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_3","purl":"pkg:maven/org.http4s/http4s-ember-core_3","ranges":[">=1.0.0-M1 <1.0.0-M47"],"fixed":["1.0.0-M47"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}