Vulnerability Description
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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Capnproto | Capnproto | < 1.4.0 |
Related Weaknesses (CWE)
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/2744b3c012b4aa3c31cefb61ec656829faPatch
- https://github.com/capnproto/capnproto/commit/e929f0ba7901a6b8f4b5ba9a4db00af432Patch
- https://github.com/capnproto/capnproto/security/advisories/GHSA-vpcq-mx5v-32wmVendor Advisory
FAQ
What is CVE-2026-32240?
CVE-2026-32240 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 trun...
How severe is CVE-2026-32240?
CVE-2026-32240 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-32240?
Check the references section above for vendor advisories and patch information. Affected products include: Capnproto Capnproto.