Cap'n Proto is a data interchange format and capability-based RPC system. Prior to 1.4.0, a negative Content-Length value was converted to unsigned, treating it as an impossibly large length instead. In theory, this bug could enable HTTP request/response smuggling. This vulnerability is fixed in 1.4.0.
{
"cwe_ids": [
"CWE-190",
"CWE-444"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32239.json",
"cna_assigner": "GitHub_M"
}{
"cpe": "cpe:2.3:a:capnproto:capnproto:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "1.4.0"
}
],
"source": [
"CPE_RANGE",
"REFERENCES"
]
}