Vulnerability DatabaseCVE-2026-32240
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CVE-2026-32240
March 12, 2026
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.
Affected Packages
https://github.com/capnproto/capnproto.git (GITHUB):
Affected version(s) >=v0.1.0 <v1.4.0
Fix Suggestion:
Update to version v1.4.0
Related Resources (5)
https://capnproto.org/capnproto-c++-1.4.0.tar.gz
https://github.com/capnproto/capnproto/commit/2744b3c012b4aa3c31cefb61ec656829fa5c0e36
https://capnproto.org/capnproto-c++-win32-1.4.0.zip
https://github.com/capnproto/capnproto/commit/e929f0ba7901a6b8f4b5ba9a4db00af43288cbb0
https://github.com/capnproto/capnproto/security/advisories/GHSA-vpcq-mx5v-32wm
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CVSS v4
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.8
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CWE-444
Numeric Truncation Error
CWE-197
EPSS
Base Score:
0.08