HIGH 7.5 NVD
CVE-2026-78659
When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler.
When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently.
References
- https://go.dev/cl/847185
- https://go.dev/cl/847314
- https://go.dev/issue/81857
- https://groups.google.com/g/golang-announce/c/U2fTuyDJznI
- https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs
This high severity vulnerability with a CVSS score of 7.5 was published on 2026-10-08 via NVD.
vulnfeed aggregates 13827 vulnerabilities from NVD, CISA KEV,
Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.