PT-2026-80511 · Julia · Capnproto Jll

Published

2026-08-12

·

Updated

2026-08-12

CVSS v3.1

6.5

Medium

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
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.

Fix

Found an issue in the description? Have something to add? Feel free to write us 👾

Related Identifiers

JLSEC-2026-1269

Affected Products

Capnproto Jll