CVE-2026-108698

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

CVSS score

8.3

EPSS probability

—

Risk score

0.8

Published

9 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

Impact on My Inventory

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Vulnerability description

CVE AI research

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DayBreach AI Explanation

Verified against sources

CVE-2026-108698 hyper-mcp OCI Plugin Signature Verification Vulnerability

Sources read

Source agreement

0/2

Evidence confidence

%37

Short explanation

hyper-mcp through 0.8.3 contains an OCI plugin signature verification vulnerability that verifies the Cosign signature of a separately resolved tag rather than the loaded manifest.

Why does it matter?

Attackers controlling registry responses can serve an unsigned malicious manifest to the loader and a signed one to Cosign, executing unauthorized WebAssembly plugins.

What should be done?

Follow vendor advisory guidance
Check for available updates

Note on uncertainty

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Chain of evidence and sources2 verified claims

hyper-mcp sürümleri 0.8.3 dahil olmak üzere, src/wasm/oci.rs içindeki load_wasm fonksiyonunda imza doğrulama atlatma zafiyeti içermektedir.

S0 · daybreach-canonical S1 · cvelist

Kayıt defteri yanıtlarını kontrol eden saldırganlar imzasız kötü amaçlı manifest sunabilir ve imzasız WebAssembly eklentilerini çalıştırabilir.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

Show the technical text from the sources

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.

CVSS 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

CWE: CWE-367

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-108698 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	hyper-mcp-rs	hyper-mcp	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
8.3	CVSS V40	HIGH	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD
8.3	CVSS V4_0	HIGH	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	CVE CNA
6.5	CVSS V31	MEDIUM	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N	NVD
6.5	CVSS V3_1	MEDIUM	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N	CVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-108698 is associated with the following CWEs:

CWE-367: Common Weakness Enumeration Entry CWE-367

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-108698 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekmiyor

Official Sources and Advisories

https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/hyper-mcp-oci-signature-manifest-toctouvendor-advisory https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/wasm/oci.rs#L79-L148vendor-advisory https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/wasm/oci.rs#L193-L224vendor-advisory https://github.com/hyper-mcp-rs/hyper-mcpvendor-advisory VulnCheck Advisory: hyper-mcp through 0.8.3 OCI Plugin Signature Verification TOCTOU Race Conditionvendor-advisory

CVSS Vector Radar Chart

8.3 / 10

Vulnerability Scoring Details

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

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User InteractionNone required

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)None

Availability (Erişilebilirlik)None

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

hyper-mcp-rs

Weakness Type (CWE & CAPEC)

CWE-367

Similar Vulnerabilities

8.3

CVE-2026-108699

hyper-mcp through 0.8.3 Improper Signature Verification of OCI WebAssembly Plugins

Vendorhyper-mcp-rsProducthyper-mcp

Patch status unknown9 h ago

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