CVE-2026-94447
Description
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.
Statement
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.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.7 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
AV:L — local go toolchain; AC:H — forged toolchain checksum plus user-chosen untrusted module proxy; UI:R — user must operate in that project; C/I/A:H — tampered toolchain execution.
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Modify Application Data; Other
Integrity checks usually use a secret key that helps authenticate the data origin. Skipping integrity checking generally opens up the possibility that new data from an invalid source can be injected.
Integrity,Other
Technical Impact: Other
Data that is parsed and used may be corrupted.
Non-Repudiation,Other
Technical Impact: Hide Activities; Other
Without a checksum check, it is impossible to determine if any changes have been made to the data after it was sent.
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