CVE catalog
CVE-2026-32239
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.
- Severity
- Medium · CVSS 6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Published
- 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, 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.
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 |
| Ubuntu | capnproto | pro | 1.1.0-2 | vulnerable |
| Ubuntu | capnproto | pro | 1.1.0-2.1 | vulnerable |
| Ubuntu | capnproto | pro | 1.1.0-2.1ubuntu0.1~esm1 | fixed |
| Opensuse | capnproto | leap 16.0 | 1.4.0-160000.1.1 | fixed |
| Opensuse | capnproto | tumbleweed | 1.4.0-2.1 | 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 |
| Ubuntu | capnproto | deb | pro | 1.1.0-2.1ubuntu0.1~esm1 | Not reported | USN-8650-1 | Not reported |
| Opensuse | capnproto | rpm | leap 16.0 | 1.4.0-160000.1.1 | Not reported | OPENSUSE-SU-2026:21062-1 | Not reported |
| Opensuse | capnproto | rpm | tumbleweed | 1.4.0-2.1 | Not reported | OPENSUSE-SU-2026:10588-1 | Not reported |
Notes
[trixie] capnproto: Minor issue [bookworm] capnproto: minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [capnproto]Affected
Details (2)
0.9.2-2· amd64 · bookwormAffected
nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
0.9.2-2· arm64 · bookwormAffected
nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
- [libcapnp-0.9.2]Affected
Source package: [capnproto]
Details (2)
0.9.2-2· amd64 · bookwormAffected
nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
0.9.2-2· arm64 · bookwormAffected
nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
- [libcapnp-dev]Affected
Source package: [capnproto]
Details (2)
0.9.2-2· amd64 · bookwormAffected
nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
0.9.2-2· arm64 · bookwormAffected
nvd · capnproto · debian · bookworm; nvd · capnproto · debian · 12
[Debian 13 (Trixie)]
- [capnproto]Affected
Details (2)
1.1.0-2· amd64 · trixieAffected
nvd · capnproto · debian · 13
1.1.0-2· arm64 · trixieAffected
nvd · capnproto · debian · 13
- [libcapnp-1.1.0]Affected
Source package: [capnproto]
Details (2)
1.1.0-2· amd64 · trixieAffected
nvd · capnproto · debian · 13
1.1.0-2· arm64 · trixieAffected
nvd · capnproto · debian · 13
- [libcapnp-dev]Affected
Source package: [capnproto]
Details (2)
1.1.0-2· amd64 · trixieAffected
nvd · capnproto · debian · 13
1.1.0-2· arm64 · trixieAffected
nvd · capnproto · debian · 13
[openSUSE Tumbleweed]
- [libcapnp-1_5_0]Unknown
Source package: [capnproto]
Details (1)
1.5.0-1.2· x86_64 · tumbleweedUnknown · Fixed:
1.4.0-2.1Version impact unknown
nvd · capnproto · opensuse · tumbleweed
- [libcapnp-devel]Unknown
Source package: [capnproto]
Details (1)
1.5.0-1.2· x86_64 · tumbleweedUnknown · Fixed:
1.4.0-2.1Version impact unknown
nvd · capnproto · opensuse · tumbleweed
- [capnproto]Fixed
Source package: [capnproto]
Details (1)
1.5.0-1.2· x86_64 · tumbleweedFixed · Fixed:
1.4.0-2.1nvd · capnproto · opensuse · tumbleweed
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_10588-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-32239]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-32239]
- [https://osv.dev/vulnerability/USN-8650-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:10588-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:21062-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-32239]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32239.json]
- [https://ubuntu.com/security/notices/USN-8650-1]
[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)]