MediumFix available
capnproto — security advisory
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.
- Products
- capnproto
- Affected versions
- 0.5.3-2ubuntu2, 0.6.1-1, 0.6.1-1ubuntu1, 0.7.0-5, 0.7.0-5build1, 0.7.0-6, 0.7.0-7build1, 0.8.0-2ubuntu2, 0.9.2-3, 1.0.1-2, 1.0.1-3, 1.0.1-4, 1.1.0-2, 1.1.0-2.1, 1.4.0-2, 1.4.0-3
- Fixed versions
- 0.6.1-1ubuntu1+esm1, 0.7.0-6ubuntu0.1~esm1, 0.8.0-2ubuntu2+esm1, 1.0.1-4ubuntu0.1~esm1, 1.1.0-2.1ubuntu0.1~esm1, 1.4.0-3build1
- CVEs
- CVE-2026-32239
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:07 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-32239
capnproto
Fixed versions: 0.6.1-1ubuntu1+esm1
capnproto
Fixed versions: 0.7.0-6ubuntu0.1~esm1
capnproto
Fixed versions: 0.8.0-2ubuntu2+esm1
capnproto
Fixed versions: 1.0.1-4ubuntu0.1~esm1
capnproto
Fixed versions: Not specified
capnproto
Fixed versions: 1.4.0-3build1
capnproto
Fixed versions: 1.1.0-2.1ubuntu0.1~esm1
Complete source record
{
"id": "5535e1799aa21dca2e514eb98a41fd8909d424941e066f5ea4964824f977c674",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-32239",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-32239",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2026-32239",
"products": [
{
"name": {
"value": "capnproto",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.6.1-1ubuntu1+esm1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "0.5.3-2ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "0.6.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "0.6.1-1ubuntu1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "capnproto",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.7.0-6ubuntu0.1~esm1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "0.7.0-5",
"evidence": "/affected/1/versions"
},
{
"value": "0.7.0-5build1",
"evidence": "/affected/1/versions"
},
{
"value": "0.7.0-6",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "capnproto",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.8.0-2ubuntu2+esm1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "0.7.0-7build1",
"evidence": "/affected/2/versions"
},
{
"value": "0.8.0-2ubuntu2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "capnproto",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.0.1-4ubuntu0.1~esm1",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": [
{
"value": "0.9.2-3",
"evidence": "/affected/3/versions"
},
{
"value": "1.0.1-2",
"evidence": "/affected/3/versions"
},
{
"value": "1.0.1-3",
"evidence": "/affected/3/versions"
},
{
"value": "1.0.1-4",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "capnproto",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.1.0-2",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "capnproto",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.4.0-3build1",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": [
{
"value": "1.1.0-2.1",
"evidence": "/affected/5/versions"
},
{
"value": "1.4.0-2",
"evidence": "/affected/5/versions"
},
{
"value": "1.4.0-3",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "capnproto",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.1.0-2.1ubuntu0.1~esm1",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": [
{
"value": "1.1.0-2",
"evidence": "/affected/6/versions"
},
{
"value": "1.1.0-2.1",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-32239",
"aliases": [
"UBUNTU-CVE-2026-32239"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.6.1-1ubuntu1+esm1"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=esm-infra%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"0.5.3-2ubuntu2",
"0.6.1-1",
"0.6.1-1ubuntu1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "0.6.1-1ubuntu1+esm1"
},
{
"binary_name": "libcapnp-0.6.1",
"binary_version": "0.6.1-1ubuntu1+esm1"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.7.0-6ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=esm-infra%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"0.7.0-5",
"0.7.0-5build1",
"0.7.0-6"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "0.7.0-6ubuntu0.1~esm1"
},
{
"binary_name": "libcapnp-0.7.0",
"binary_version": "0.7.0-6ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.8.0-2ubuntu2+esm1"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
"0.7.0-7build1",
"0.8.0-2ubuntu2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "0.8.0-2ubuntu2+esm1"
},
{
"binary_name": "libcapnp-0.8.0",
"binary_version": "0.8.0-2ubuntu2+esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.0.1-4ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=esm-apps%2Fnoble",
"ecosystem": "Ubuntu:Pro:24.04:LTS"
},
"versions": [
"0.9.2-3",
"1.0.1-2",
"1.0.1-3",
"1.0.1-4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "1.0.1-4ubuntu0.1~esm1"
},
{
"binary_name": "libcapnp-1.0.1",
"binary_version": "1.0.1-4ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"1.1.0-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "1.1.0-2"
},
{
"binary_name": "libcapnp-1.1.0",
"binary_version": "1.1.0-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.4.0-3build1"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"1.1.0-2.1",
"1.4.0-2",
"1.4.0-3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "1.4.0-3build1"
},
{
"binary_name": "libcapnp-1.4.0",
"binary_version": "1.4.0-3build1"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.1.0-2.1ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "capnproto",
"purl": "pkg:deb/ubuntu/capnproto?arch=source&distro=esm-apps%2Fresolute",
"ecosystem": "Ubuntu:Pro:26.04:LTS"
},
"versions": [
"1.1.0-2",
"1.1.0-2.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-32239.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "capnproto",
"binary_version": "1.1.0-2.1ubuntu0.1~esm1"
},
{
"binary_name": "libcapnp-1.1.0",
"binary_version": "1.1.0-2.1ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
}
],
"modified": "2026-10-17T12:58:09.252696981Z",
"provider": "osv",
"upstream": [
"CVE-2026-32239"
],
"references": [
"https://ubuntu.com/security/CVE-2026-32239",
"https://www.cve.org/CVERecord?id=CVE-2026-32239",
"https://github.com/capnproto/capnproto/security/advisories/GHSA-qjx3-pp3m-9jpm",
"https://ubuntu.com/security/notices/USN-8650-1"
]
},
"related_cves": [
{
"value": "CVE-2026-32239",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 358235,
"published_at": "2026-03-12T20:16:00+00:00"
}