Cap'n Proto is a data interchange format and capability-based RPC system. Prior to 1.4.0, when using Transfer-Encoding: chunked, if a chunk's size parsed to a value of 2^64 or larger, it would be truncated to a 64-bit integer. In theory, this bug could enable HTTP request/response smuggling. This vulnerability is fixed in 1.4.0.
History

Thu, 12 Mar 2026 20:00:00 +0000

Type Values Removed Values Added
Description Cap'n Proto is a data interchange format and capability-based RPC system. Prior to 1.4.0, when using Transfer-Encoding: chunked, if a chunk's size parsed to a value of 2^64 or larger, it would be truncated to a 64-bit integer. In theory, this bug could enable HTTP request/response smuggling. This vulnerability is fixed in 1.4.0.
Title Cap'n Proto: Integer overflow in KJ-HTTP chunk size
Weaknesses CWE-197
CWE-444
References
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-12T19:35:57.374Z

Reserved: 2026-03-11T14:47:05.684Z

Link: CVE-2026-32240

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-12T20:16:05.190

Modified: 2026-03-12T21:07:53.427

Link: CVE-2026-32240

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.