CVE-2026-108699
hyper-mcp through 0.8.3 Improper Signature Verification of OCI WebAssembly Plugins
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
hyper-mcp through 0.8.3 contains an improper signature verification vulnerability that allows attackers to load malicious WebAssembly plugins because cosign_verify_args() accepts any signer identity and OIDC issuer by default. Attackers controlling a plugin image reference can sign a malicious image with a free Sigstore keyless certificate to execute plugins with configured host, filesystem, and environment capabilities.
| CWE | CWE-347 |
| Vendor | hyper-mcp-rs |
| Product | hyper-mcp |
| Published | Oct 11, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
None
Affected Versions
hyper-mcp-rs / hyper-mcp
0 ≤ 0.8.3
References
hackmd.io: https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/hyper-mcp-oci-signature-manifest-toctou github.com: https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/wasm/oci.rs#L157-L190 github.com: https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/config.rs#L138-L170 github.com: https://github.com/hyper-mcp-rs/hyper-mcp vulncheck.com: https://www.vulncheck.com/advisories/hyper-mcp-through-0.8.3-improper-signature-verification-of-oci-webassembly-plugins
Credits
hieuPenguinnn