CVE-2026-76847

act (nektos/act) versions 0.2.81 through 0.2.89 are affected by a missing authorization flaw in the Artifacts V4 backend , which is started whenever a workflow uses actions/upload-artifact@v4 or actions/download-artifact@v4. Three compounding issues enable unauthenticated artifact access: (1) val...

EUVD-2026-64852

act starts an HTTP Artifacts V4 backend whenever a workflow uses actions/upload-artifact@v4 or actions/download-artifact@v4. The control-plane RPCs of that backend, including CreateArtifact, GetSignedArtifactURL, ListArtifacts, FinalizeArtifact and DeleteArtifact, accept a caller-supplied...