Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb
Summary
| CVE | CVE-2026-56864 |
|---|---|
| State | PUBLISHED |
| Assigner | Go |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-13 22:17:22 UTC |
| Updated | 2026-08-14 17:19:14 UTC |
| 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 |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS: 0.002480000 probability, percentile 0.164560000 (date 2026-08-16)
Problem Types: CWE-347 | CWE-347: Improper Verification of Cryptographic Signature | CWE-347 CWE-347 Improper Verification of Cryptographic Signature
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Go Toolchain | Cmd/go | affected 1.25.13 semver | Not specified |
| CNA | Go Toolchain | Cmd/go | affected 1.26.0-0 1.26.6 semver | Not specified |
| CNA | Go Toolchain | Cmd/go | affected 1.27.0-0 1.27.0-rc.3 semver | Not specified |
| CNA | Golang.orgxmod | Golang.org/x/mod/sumdb | affected 0.40.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| groups.google.com/g/golang-announce/c/94pEornpRlI | [email protected] | groups.google.com | |
| pkg.go.dev/vuln/GO-2026-6180 | [email protected] | pkg.go.dev | |
| go.dev/issue/80745 | [email protected] | go.dev | |
| go.dev/cl/815020 | [email protected] | go.dev | |
| go.dev/cl/815000 | [email protected] | go.dev | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: mundur (en)
There are currently no legacy QID mappings associated with this CVE.