CVE-2026-108699

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-10-11. A secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated
6.5EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 6.5Exploit: No code on recordExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The CVE record's CNA (VulnCheck) lists hyper-mcp-rs hyper-mcp versions up to and including 0.8.3 as affected. No release containing a fix is confirmed on record.

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.

CVSS v3
6.5
EG Score
6.5MEDIUMhigh confidence
EG Risk
45
EG Risk 45/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
The EG Score, 6.5 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 11, 2026

Last Modified

October 13, 2026

Advisory Details (5)

Auto-updated Oct 11, 2026
No fix on record yet.
Web page

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

https://www.vulncheck.com/advisories/hyper-mcp-through-0.8.3-improper-signature-verification-of-oci-webassembly-plugins
Web page

hyper-mcp OCI plugin loader: Cosign signature verification is not bound to the resolved manifest, so a mutable tag can load unverified WebAssembly - HackMD

https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/hyper-mcp-oci-signature-manifest-toctou
Web page

hyper-mcp/src/wasm/oci.rs at v0.8.3 · hyper-mcp-rs/hyper-mcp · GitHub

https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/wasm/oci.rs#L157-L190
Web page

hyper-mcp/src/config.rs at v0.8.3 · hyper-mcp-rs/hyper-mcp · GitHub

https://github.com/hyper-mcp-rs/hyper-mcp/blob/v0.8.3/src/config.rs#L138-L170
Web page

GitHub - hyper-mcp-rs/hyper-mcp: 📦️ A fast, secure MCP server that extends its capabilities through WebAssembly plugins. · GitHub

https://github.com/hyper-mcp-rs/hyper-mcp

Vendor Advisories for CVE-2026-108699(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 12× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-13 20:26 UTCEG score recompute
  2. 2026-10-13 20:26 UTCGHSA enrichmentGHSA-4j25-h357-wg62 · GitHub severity HIGH · GitHub CVSS 6.5
  3. 2026-10-13 20:02 UTCEG score recompute
  4. 2026-10-13 20:01 UTCGHSA enrichmentGHSA-4j25-h357-wg62 · GitHub severity HIGH · GitHub CVSS 6.5
  5. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  6. 2026-10-12 16:38 UTCEG score recompute
  7. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  8. 2026-10-11 20:13 UTCEG score recompute
  9. 2026-10-11 18:26 UTCEG score recompute
  10. 2026-10-11 14:17 UTCEG score recompute
  11. 2026-10-11 13:39 UTCEG score recomputeFirst assessed: 6.5 MEDIUM
  12. 2026-10-11 13:36 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-108699?
CVE-2026-108699 is a medium-severity vulnerability; its CVE record was published on October 11, 2026. hyper-mcp through 0.8.3 contains an improper signature verification vulnerability that allows attackers to load malicious WebAssembly plugins because cosignverifyargs() accepts any signer identity and OIDC issuer by default. Attackers controlling a plugin image reference can sign a malicious image…
When was CVE-2026-108699 made public?
CVE-2026-108699 was made public on October 11, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on October 11, 2026. EchelonGraph's copy of the record carries a last-modified date of October 13, 2026; the record at its source may have been updated since.
Is CVE-2026-108699 actively exploited?
CVE-2026-108699 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-108699?
CVE-2026-108699 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-108699?
No fix for CVE-2026-108699 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The CVE record's CNA (VulnCheck) lists hyper-mcp-rs hyper-mcp versions up to and including 0.8.3 as affected. No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-108699 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-108699

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