CVE-2026-94447

A flaw was found in the Go toolchain (cmd/go). When a user works inside a malicious Go project that forges a golang.org/toolchain go.sum entry and uses an untrusted Go module proxy, cmd/go can skip the canonical checksum database check for toolchain downloads. A tampered toolchain may then be downloaded and executed.

This issue is rated Moderate. Exploitation requires a developer to operate inside a maliciously crafted Go project and to use an untrusted module proxy. The golang toolchain is primarily a development and build-time component, and this is not a typical Red Hat product runtime configuration. Successful exploitation can result in execution of a tampered Go toolchain as the user running the go command.

Go versions before 1.21 do not implement automatic golang.org/toolchain downloads and are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Do not point GOPROXY or related module proxy settings at untrusted proxies, and do not build untrusted Go projects while using a non-default proxy. Prefer the default Go module proxy and checksum database. Setting GOTOOLCHAIN=local also avoids downloading toolchains.