Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s chunk decoder trims the chunk-size token and accepts leading plus or minus signs instead of requiring one or more hexadecimal digits followed by the required CRLF. When an intermediary forwards chunked data without re-encoding and interprets malformed chunk boundaries differently, an unauthenticated attacker can create TE.TE request smuggling that bypasses intermediary controls, poisons caches, or hijacks the request queue. The same response-path leniency can enable response smuggling against an ember-client used as a gateway when the upstream is malicious or compromised. 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-2026-69216.json"
}{
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "0.23.35"
},
{
"introduced": "1.0.0-M1"
},
{
"fixed": "1.0.0-M47"
}
],
"source": [
"AFFECTED_FIELD",
"REFERENCES"
]
}