CVE catalog

CVE-2026-32240

Severity: Medium · CVSS 6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Published: Mar 12, 2026, 7:35:57 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.21% · Oct 25, 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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	capnproto	sid	`1.5.0-2`	fixed
Debian	capnproto	forky	`1.5.0-2`	fixed
Debian	capnproto	trixie	`1.1.0-2`	vulnerable
Debian	capnproto	bookworm	`0.9.2-2`	vulnerable
Cpe	capnproto	Not reported	Not reported	vulnerable
Ubuntu	capnproto	noble	`1.0.1-4ubuntu0.1~esm1`	fixed
Ubuntu	libcapnp-1.0.1	noble	`1.0.1-4ubuntu0.1~esm1`	fixed
Ubuntu	libcapnp-dev	noble	`1.0.1-4ubuntu0.1~esm1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	capnproto	source	sid	`1.4.0-2`	not yet assigned	Not reported	[1130877]
Debian	capnproto	source	forky	`1.4.0-2`	not yet assigned	Not reported	[1130877]
Debian	capnproto	source	trixie	`(unfixed)`	not yet assigned	Not reported	[1130877]
Debian	capnproto	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1130877]
Ubuntu	capnproto	deb	noble	`1.0.1-4ubuntu0.1~esm1`	Not reported	Not reported	Not reported
Ubuntu	libcapnp-1.0.1	deb	noble	`1.0.1-4ubuntu0.1~esm1`	Not reported	Not reported	Not reported
Ubuntu	libcapnp-dev	deb	noble	`1.0.1-4ubuntu0.1~esm1`	Not reported	Not reported	Not reported

[Debian bug #1130877]

Notes

[trixie] capnproto: Minor issue [bookworm] capnproto: minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[capnproto]Affected
Details (2)
- 0.9.2-2 · amd64 · bookworm
  Affected
  nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
- 0.9.2-2 · arm64 · bookworm
  Affected
  nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
[libcapnp-0.9.2]Affected
Source package: [capnproto]
Details (2)
- 0.9.2-2 · amd64 · bookworm
  Affected
  nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
- 0.9.2-2 · arm64 · bookworm
  Affected
  nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
[libcapnp-dev]Affected
Source package: [capnproto]
Details (2)
- 0.9.2-2 · amd64 · bookworm
  Affected
  nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
- 0.9.2-2 · arm64 · bookworm
  Affected
  nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12

[Debian 13 (Trixie)]

[capnproto]Affected
Details (2)
- 1.1.0-2 · amd64 · trixie
  Affected
  nvd · capnproto · debian · 13
- 1.1.0-2 · arm64 · trixie
  Affected
  nvd · capnproto · debian · 13
[libcapnp-1.1.0]Affected
Source package: [capnproto]
Details (2)
- 1.1.0-2 · amd64 · trixie
  Affected
  nvd · capnproto · debian · 13
- 1.1.0-2 · arm64 · trixie
  Affected
  nvd · capnproto · debian · 13
[libcapnp-dev]Affected
Source package: [capnproto]
Details (2)
- 1.1.0-2 · amd64 · trixie
  Affected
  nvd · capnproto · debian · 13
- 1.1.0-2 · arm64 · trixie
  Affected
  nvd · capnproto · debian · 13

Observed: Oct 24, 2026, 12:37:12 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]