CVE-2026-94447: CWE-354: Improper Validation of Integrity Check Value in Go toolchain cmd/go
Description
CVE-2026-94447 is a vulnerability in the Go toolchain's cmd/go component involving improper validation of integrity check values. It allows a user working inside a malicious Go project with a bogus golang.org/toolchain go.sum entry and a malicious GOMODPROXY to bypass the intended checksum verification. The issue is addressed by ensuring that golang.org/toolchain always fetches the canonical checksum from the network.
Affected software
Go toolchain
cmd/go
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-354) in the Go toolchain's cmd/go allows bypassing checksum validation when a user operates within a malicious Go project that defines a fake golang.org/toolchain go.sum entry and uses a malicious GOMODPROXY. The fix enforces that golang.org/toolchain always retrieves the canonical checksum from the network, preventing checksum bypass.
Potential Impact
An attacker controlling a malicious Go project and GOMODPROXY can bypass checksum validation, potentially leading to the use of tampered or malicious dependencies. This undermines the integrity guarantees of the Go module system for affected versions.
Mitigation Recommendations
Upgrade to a fixed version of the Go toolchain. The affected versions are all releases before 1.26.9 and versions from 1.27.0-0 up to but excluding 1.27.2. Users should update to 1.26.9 or later, or 1.27.2 or later to ensure the vulnerability is patched. No vendor advisory content is provided, so patch status is inferred from affected versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Go
- Date Reserved
- 2026-09-21T16:43:04.757Z
- State
- PUBLISHED
Threat ID: 6ac821662cdf04f656417218
Added to database: 10/08/2026, 23:04:06 UTC
Last enriched: 10/08/2026, 23:19:03 UTC
Last updated: 10/08/2026, 23:19:11 UTC
Views: 4
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