CVE-2026-56864

Description

A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the transparency log. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy

References

• https://go.dev/cl/815000
• https://go.dev/cl/815020
• https://go.dev/issue/80745
• https://groups.google.com/g/golang-announce/c/94pEornpRlI
• https://pkg.go.dev/vuln/GO-2026-6180