Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember HTTP/1.1 does not reject messages containing both Transfer-Encoding and Content-Length, so an intermediary and Ember can select different body framing rules. When ember-server is behind a keep-alive intermediary that forwards both headers and frames by Content-Length, an unauthenticated attacker can smuggle a second request, bypass intermediary access controls, poison caches, or cause a victim request to be joined to an attacker-controlled prefix. The shared response parser can also desynchronize an ember-client connection when a malicious or compromised upstream sends both headers. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-444"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69204.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "0.23.35"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"introduced": "1.0.0-M1"
},
{
"fixed": "1.0.0-M47"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "9feaf8677951a52af906ae9664ff6f0543d9d810"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v0.23.35",
"range": [
{
"fixed": "a83f5f4f7e14c5b4d4a91dd71b105cbbbb391298"
}
],
"source": "REFERENCES_TAG"
},
{
"original_tag": "v1.0.0-M47",
"range": [
{
"fixed": "6083780a3009bd7b26033b0ceb3d32c658b0377e"
}
],
"source": "REFERENCES_TAG"
}
]
}