CVE-2026-108698

hyper-mcp through 0.8.3 OCI Plugin Signature Verification TOCTOU Race Condition

Published Oct 11, 2026 CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed
Description
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

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Hyper-mcp-rs
Hyper-mcp-rs hyper-mcp
Vendors & Products Hyper-mcp-rs
Hyper-mcp-rs hyper-mcp
Type Values Removed Values Added
Description 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.
Title hyper-mcp through 0.8.3 OCI Plugin Signature Verification TOCTOU Race Condition
Weaknesses CWE-367
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N'}

cvssV4_0

{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 13, 2026, 4:59 PM
Reserved
Oct 10, 2026, 11:08 PM
Status
Deferred
Published
Oct 11, 2026, 2:17 PM
Modified
Oct 16, 2026, 7:18 PM