CVE-2026-32239

MEDIUM

Cap'n Proto <1.4.0 KJ-HTTP - Content-Length Integer Overflow

Title source: manual
STIX 2.1

Description

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.

References (5)

Core 5

Scores

CVSS v3 6.5
EPSS 0.0021
EPSS Percentile 10.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-444 CWE-190
Status published
Products (1)
capnproto/capnproto < 1.4.0
Published Mar 12, 2026
Tracked Since Mar 13, 2026