{"id":"CVE-2026-69218","state":"PUBLISHED","title":"Http4s Ember HTTP/2: unbounded continuation frame accumulation","description":"Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, When Ember receives an HTTP/2 HEADERS or PUSH_PROMISE frame without END_HEADERS, H2Connection buffers the header block and subsequent CONTINUATION fragments without a size bound. A remote peer can keep an incomplete block open and exhaust heap memory before request decoding, affecting an ember-server or ember-client configured with withHttp2. The remediation tracks accumulated size against SETTINGS_MAX_HEADER_LIST_SIZE derived from EmberServerBuilder.maxHeaderSize or EmberClientBuilder.maxResponseHeaderSize, sends GOAWAY when the limit is exceeded, and applies receiveHeadersTimeout to incomplete blocks. This issue is fixed in versions 0.23.35 and 1.0.0-M47.","publishedAt":"2026-09-15T19:22:57.407Z","updatedAt":"2026-09-17T16:47:13.590Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["http4s http4s"],"affected":[{"vendor":"http4s","product":"http4s","versions":[{"version":"< 0.23.35","status":"affected"},{"version":">= 1.0.0-M1, < 1.0.0-M47","status":"affected"}]}],"references":["https://github.com/http4s/http4s/security/advisories/GHSA-cp4q-fqw9-4hf6","https://github.com/http4s/http4s/commit/6e8eccd64a6a74ab4811897881e95e0e1b3a818e","https://github.com/http4s/http4s/commit/f9dcca4f5a17992ac0972fafd7920f9bc12cdc51","https://github.com/http4s/http4s/releases/tag/v0.23.35","https://github.com/http4s/http4s/releases/tag/v1.0.0-M47"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/69xxx/CVE-2026-69218.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-69218","state":"PUBLISHED","datePublished":"2026-09-15T19:22:57.407Z","dateUpdated":"2026-09-17T16:47:13.590Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-03T16:57:50.125Z"},"containers":{"cna":{"title":"Http4s Ember HTTP/2: unbounded continuation frame accumulation","descriptions":[{"lang":"en","value":"Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, When Ember receives an HTTP/2 HEADERS or PUSH_PROMISE frame without END_HEADERS, H2Connection buffers the header block and subsequent CONTINUATION fragments without a size bound. A remote peer can keep an incomplete block open and exhaust heap memory before request decoding, affecting an ember-server or ember-client configured with withHttp2. The remediation tracks accumulated size against SETTINGS_MAX_HEADER_LIST_SIZE derived from EmberServerBuilder.maxHeaderSize or EmberClientBuilder.maxResponseHeaderSize, sends GOAWAY when the limit is exceeded, and applies receiveHeadersTimeout to incomplete blocks. This issue is fixed in versions 0.23.35 and 1.0.0-M47."}],"affected":[{"vendor":"http4s","product":"http4s","versions":[{"version":"< 0.23.35","status":"affected"},{"version":">= 1.0.0-M1, < 1.0.0-M47","status":"affected"}]}],"references":[{"url":"https://github.com/http4s/http4s/security/advisories/GHSA-cp4q-fqw9-4hf6","name":"https://github.com/http4s/http4s/security/advisories/GHSA-cp4q-fqw9-4hf6","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/http4s/http4s/commit/6e8eccd64a6a74ab4811897881e95e0e1b3a818e","name":"https://github.com/http4s/http4s/commit/6e8eccd64a6a74ab4811897881e95e0e1b3a818e","tags":["x_refsource_MISC"]},{"url":"https://github.com/http4s/http4s/commit/f9dcca4f5a17992ac0972fafd7920f9bc12cdc51","name":"https://github.com/http4s/http4s/commit/f9dcca4f5a17992ac0972fafd7920f9bc12cdc51","tags":["x_refsource_MISC"]},{"url":"https://github.com/http4s/http4s/releases/tag/v0.23.35","name":"https://github.com/http4s/http4s/releases/tag/v0.23.35","tags":["x_refsource_MISC"]},{"url":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47","name":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-15T19:22:57.407Z"},"source":{"advisory":"GHSA-cp4q-fqw9-4hf6","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-17T16:46:52.034934Z","id":"CVE-2026-69218","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-17T16:47:13.590Z"}}]}}}