CVE-2026-32240

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://capnproto.org/capnproto-c++-1.4.0.tar.gz	Product
https://capnproto.org/capnproto-c++-win32-1.4.0.zip	Product
https://github.com/capnproto/capnproto/commit/2744b3c012b4aa3c31cefb61ec656829fa5c0e36	Patch
https://github.com/capnproto/capnproto/commit/e929f0ba7901a6b8f4b5ba9a4db00af43288cbb0	Patch
https://github.com/capnproto/capnproto/security/advisories/GHSA-vpcq-mx5v-32wm	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:capnproto:capnproto:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-03-12 20:16

Updated : 2026-03-18 17:01

NVD link : CVE-2026-32240

Mitre link : CVE-2026-32240

CVE.ORG link : CVE-2026-32240

JSON object : View

Products Affected

capnproto

capnproto

CWE

CWE-197

Numeric Truncation Error

CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

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