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Dismissed
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Permalink CVE-2026-45781
3.5 LOW
  • CVSS version (CVSS): 3.1
  • Attack Vector (AV): Network (N)
  • Attack Complexity (AC): Low (L)
  • Privileges Required (PR): Low (L)
  • User Interaction (UI): Required (R)
  • Scope (S): Unchanged (U)
  • Confidentiality (C): None (N)
  • Integrity (I): Low (L)
  • Availability (A): None (N)
  • Modified Attack Vector (MAV): Network (N)
  • Modified Attack Complexity (MAC): Low (L)
  • Modified Privileges Required (MPR): Low (L)
  • Modified User Interaction (MUI): Required (R)
  • Modified Confidentiality (MC): None (N)
  • Modified Scope (MS): Unchanged (U)
  • Modified Integrity (MI): Low (L)
  • Modified Availability (MA): None (N)
updated 3 months, 4 weeks ago by @LeSuisse Activity log
  • Created suggestion
  • @LeSuisse dismissed (not in Nixpkgs)
MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.9, OCI ownership validation skips label-match check when upstream OCI registry returns HTTP 429, letting any authenticated publisher bind their io.github.<user>/* namespace to OCI images they do not control. internal/validators/registries/oci.go:104-119 fails open on http.StatusTooManyRequests: when the registry's anonymous fetch to the upstream OCI registry is rate-limited, ValidateOCI returns nil and the publish is accepted without ever running the io.modelcontextprotocol.server.name label-match check at lines 122-141. That label check is the only cross-system ownership proof the registry applies to OCI packages — every other registry type (NPM, PyPI, NuGet, MCPB) treats a non-200 upstream response as a hard error. This vulnerability is fixed in 1.7.9.

Affected products

registry
  • ==< 1.7.9

Matching in nixpkgs

pkgs.crane

Tools for interacting with remote images and registries including crane and gcrane

pkgs.gcrane

Tools for interacting with remote images and registries including crane and gcrane

pkgs.go-containerregistry

Tools for interacting with remote images and registries including crane and gcrane

Package maintainers