Bug 2447117 (CVE-2026-32240) - CVE-2026-32240 capnproto: Cap'n Proto: Integer overflow in KJ-HTTP chunk size
Summary: CVE-2026-32240 capnproto: Cap'n Proto: Integer overflow in KJ-HTTP chunk size
Keywords:
Status: NEW
Alias: CVE-2026-32240
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-03-12 20:02 UTC by OSIDB Bzimport
Modified: 2026-03-13 11:55 UTC (History)
0 users

Fixed In Version:
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Description OSIDB Bzimport 2026-03-12 20:02:03 UTC 
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.
Comment 2 TEJ RATHI 2026-03-13 11:55:05 UTC 
Upstream Advisory:
https://github.com/capnproto/capnproto/security/advisories/GHSA-vpcq-mx5v-32wm

Upstream Commits:

master (1.x) branch: https://github.com/capnproto/capnproto/commit/2744b3c012b4aa3c31cefb61ec656829fa5c0e36
v2 branch: https://github.com/capnproto/capnproto/commit/e929f0ba7901a6b8f4b5ba9a4db00af43288cbb0
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