CVE-2026-56865

Description

A malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go module cache. This attack allows for a malicious GOPROXY to serve malicious module content that cannot be detected by evaluating the transparency log. All tiles are now correctly verified against their parents. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy

CVSS Metrics

• v3.1•HIGH•Score: 8.4CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.11%• Percentile: 1%

Techniques & Countermeasures

• CWE-347•Improper Verification of Cryptographic Signature

  The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Affected Systems

• chainguard•aactl

  < 0.4.12-r69

• chainguard•agentbeat

  < 0

• chainguard•agentbeat-fips

  < 0

• chainguard•amazon-cloudwatch-agent

  < 0

• chainguard•amazon-eks-ami

  < 0

• chainguard•amazon-eks-ami-fips

  < 0

• chainguard•amazon-k8s-cni

  < 0

• chainguard•amazon-k8s-cni-fips

  < 0

• chainguard•apply-cve-bump

  < 0

• chainguard•argo-cd-3.3-compat

  < 0

• chainguard•argo-events

  < 0

• chainguard•argo-events-fips

  < 0

• chainguard•art

  < 0

• chainguard•atlantis

  < 0

• chainguard•atlantis-fips

  < 0

• chainguard•atlas

  < 0

• chainguard•atlas-1.0

  < 0

• chainguard•atlas-1.0-fips

  < 0

• chainguard•atlas-1.1

  < 0

• chainguard•atlas-1.1-fips

  < 0

• chainguard•atlas-1.2

  < 0

• chainguard•atlas-1.3

  < 0

• chainguard•atlas-fips

  < 0

• chainguard•atlas-fips-1.2

  < 0

• chainguard•atlas-fips-1.3

  < 0

• chainguard•aws-otel-collector-fips

  < 0

• chainguard•aws-otel-collector-healthcheck-fips

  < 0

• chainguard•azure-service-operator

  < 0

• chainguard•azurefile-csi-1.32

  < 0

• chainguard•bank-vaults-template

  < 0

• chainguard•bento

  < 0

• chainguard•bento-fips

  < 0

• chainguard•blob-csi-1.27

  < 0

• chainguard•bom

  < 0

• chainguard•boringssl-fips-static-20240407-tools

  < 0

• chainguard•buf

  < 0

• chainguard•buildah

  < 0

• chainguard•buildah-fips

  < 0

• chainguard•buildkitd

  < 0

• chainguard•buildkitd-fips

  < 0

• chainguard•buildkite-agent

  < 0

• chainguard•buildkite-agent-fips

  < 0

• chainguard•calico-felix-3.32

  < 0

• chainguard•calico-felix-fips-3.32

  < 0

• chainguard•calico-goldmane-3.31

  < 0

• chainguard•calico-key-cert-provisioner-3.31

  < 0

• chainguard•capslock

  < 0

• chainguard•cargobump

  < 0

• chainguard•cass-operator

  < 0

• chainguard•cass-operator-fips

  < 0

Showing first 50 affected entries in server-rendered view.

References (9)

• https://go.dev/issue/80744
• https://groups.google.com/g/golang-announce/c/94pEornpRlI
• https://go.dev/cl/814960
• https://go.dev/cl/815020
• https://pkg.go.dev/vuln/GO-2026-6179
• https://security-tracker.debian.org/tracker/CVE-2026-56865
• https://ubuntu.com/security/CVE-2026-56865
• https://www.cve.org/CVERecord?id=CVE-2026-56865
• https://github.com/golang/go/issues/80744