Live › vulnerability › CVE-2026-78659
Go to dashboardA malicious client can send an HTTP/2 request with a Trailer header that declares a very large number of fields, making a Go net/http server allocate a disproportionate amount of memory. An attacker can exhaust server memory and cause denial of service, bypassing the header count and size limits.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 19:13 UTC, 0h before NVD. All times on this page are UTC.
| Product | Ecosystem | Affected | Fixed in |
|---|---|---|---|
| stdlib | go | < 1.26.9 | 1.26.9 |
| stdlib | go | >= 1.27.0-0, < 1.27.2 | 1.27.2 |
| golang.org/x/net | go | < 0.60.0 | 0.60.0 |
1.26.9, or 1.27.0 through 1.27.10.60.01.26.9 or 1.27.2 and rebuild the server binaries0.60.0 and rebuildEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
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.
This page as .md · .json · in your agent: get_signal("CVE-2026-78659")
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