---
id: CVE-2026-108698
title: >-
  hyper-mcp through 0.8.3 contains a signature verification bypass vulnerability
  in load_wasm in src/wasm/oci.rs that verifies the Cosign signature of a
  separately resolved tag rather than the loaded manifest
summary: >-
  hyper-mcp through 0.8.3 contains a signature verification bypass vulnerability
  in load_wasm in src/wasm/oci.rs that verifies the Cosign signature of a
  separately resolved tag rather than the loaded manifest. Attackers controlling
  registr…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N'
cwe:
  - CWE-367
published: '2026-10-11'
updated: '2026-10-11'
sourceUpdated: '2026-10-11T14:17:04.113'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-108698'
references:
  - url: 'https://github.com/hyper-mcp-rs/hyper-mcp'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/wasm/oci.rs#L193-L224
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/wasm/oci.rs#L79-L148
    label: disclosure@vulncheck.com
  - url: >-
      https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/hyper-mcp-oci-signature-manifest-toctou
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/hyper-mcp-through-0.8.3-oci-plugin-signature-verification-toctou-race-condition
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-12T14:50:34.049Z'
---

## Overview

hyper-mcp through 0.8.3 contains a signature verification bypass vulnerability in load_wasm in src/wasm/oci.rs that verifies the Cosign signature of a separately resolved tag rather than the loaded manifest. Attackers controlling registry responses for the tag can serve an unsigned malicious manifest to the loader and a signed one to Cosign, executing unsigned WebAssembly plugins with configured host capabilities.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.