CVE-2026-61542

HIGHPre-NVD 8.68.6
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (23rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-112412 (ENISA EUVD)Source: ENISA EUVD

8.6EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (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: 0.3%CVSS: 8.6Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Gearboy is a Game Boy, Game Boy Color, and Super Game Boy emulator and debugger with an embedded MCP server. Gearsystem, the affected component, has an optional --mcp-http mode that accepts unauthenticated MCP requests from any reachable network peer despite localhost-only documentation and logging. In the described platforms/shared/desktop/mcp/mcp_transport.h transport, the socket binds INADDR_ANY, normally on port 7777, and POST requests to /mcp reach dispatch without Authorization, Host, or Origin checks. Responses and OPTIONS advertise Access-Control-Allow-Origin: *. A peer can initialize an MCP session and invoke exposed emulator/debugging operations; even a garbage bearer token does not block dispatch, while a loopback-bind negative control prevents network access. The reported impact is bounded to the emulator process, debugging state, and local files accepted as media, rather than demonstrated host code execution. Gearboy 3.8.7 contains a patch.

CVSS v3
8.6
EG Score
8.6HIGHmedium confidence
EG Risk
70
EG Risk 70/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity86% × 45%
Impact severity (EG Severity): CVSS 8.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.6): severity, escalated by confirmed exploitation. This CVE's 8.6 is its impact severity (EG Severity), not escalated.

EG Severity
8.6 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-09). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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 28, 2026

Last Modified

November 3, 2026

Advisory Details (3)

Auto-updated Oct 28, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
GitHub release Patch Available

Gearboy 3.8.7

Patch available: drhelius/Gearboy 3.8.7

https://github.com/drhelius/Gearboy/releases/tag/3.8.7
GitHub commit

commit e2ead98e2fac (drhelius/Gearboy)

Fix landed in drhelius/Gearboy commit e2ead98e2fac — awaiting tagged release

https://github.com/drhelius/Gearboy/commit/e2ead98e2fac41e9df5a499e9e421c6a0e73f1bc
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Gearsystem MCP HTTP transport binds all interfaces without authentication while documented as localhost · Advisory · drhelius/Gearboy · GitHub

https://github.com/drhelius/Gearboy/security/advisories/GHSA-fmvx-487g-mrww

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 17× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  3. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  4. 2026-11-10 01:54 UTCEchelonGraph re-scored
  5. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  6. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  7. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  8. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  9. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  10. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  11. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  12. 2026-11-03 14:30 UTCEchelonGraph re-scored
  13. 2026-11-03 14:19 UTCEchelonGraph re-scored
  14. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  15. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  16. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  17. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  18. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  19. 2026-10-28 20:27 UTCEchelonGraph re-scored
  20. 2026-10-28 20:01 UTCENISA EUVD ID recordedEUVD-2026-112412 · Source: ENISA EUVD
  21. 2026-10-28 19:53 UTCEchelonGraph re-scoredFirst assessed: 8.6 HIGH
  22. 2026-10-28 19:53 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-61542?
CVE-2026-61542 is a high-severity vulnerability; its CVE record was published on October 28, 2026. Gearboy is a Game Boy, Game Boy Color, and Super Game Boy emulator and debugger with an embedded MCP server. Gearsystem, the affected component, has an optional --mcp-http mode that accepts unauthenticated MCP requests from any reachable network peer despite localhost-only documentation and…
When was the CVE record for CVE-2026-61542 published?
The CVE record for CVE-2026-61542 was published on October 28, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 3, 2026; the record at its source may have been updated since.
Is CVE-2026-61542 actively exploited?
CVE-2026-61542 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-61542?
CVE-2026-61542 has a CVSS base score of 8.6 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-61542?
A fix for CVE-2026-61542 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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