CVE-2026-32240Cap'n Proto is a data interchange format and capability-based RPC system.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 6.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- Weakness (CWE)
- CWE-197, CWE-444
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
capnproto capnproto capnproto:capnproto | before 1.4.0 | NVD |
References
- https://capnproto.org/capnproto-c++-1.4.0.tar.gzproduct
- https://capnproto.org/capnproto-c++-win32-1.4.0.zipproduct
- https://github.com/capnproto/capnproto/commit/2744b3c012b4aa3c31cefb61ec656829fa5c0e36patch
- https://github.com/capnproto/capnproto/commit/e929f0ba7901a6b8f4b5ba9a4db00af43288cbb0patch
- https://github.com/capnproto/capnproto/security/advisories/GHSA-vpcq-mx5v-32wmvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.