CVE-2026-102878

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-09-29. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
8.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.1Exploit: Elevated riskExposed services: Not assessed

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

mcp-chrome-bridge through 1.0.31 contains an origin validation error in the native-server HTTP API that allows attackers to bypass CORS restrictions. Attackers can craft malicious web pages that make cross-origin requests to the local server and invoke browser automation tools including script execution, page content reading, and screenshot capture.

CVSS v3
8.1
EG Score
8.1HIGHhigh confidence
EG Risk
52
EG Risk 52/100CISA SSVC

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
Severity81% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
13th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 29, 2026

Last Modified

September 30, 2026

Advisory Details (4)

Auto-updated Sep 29, 2026
No patch confirmed yet.
generic

mcp-chrome-bridge through 1.0.31 CORS Origin Bypass | Advisories | VulnCheck

https://www.vulncheck.com/advisories/mcp-chrome-bridge-through-1.0.31-cors-origin-bypass
generic

GitHub - hangwin/mcp-chrome: Chrome MCP Server is a Chrome extension-based Model Context Protocol (MCP) server that exposes your Chrome browser functionality to AI assistants like Claude, enabling complex browser automation, content analysis, and semantic search. · GitHub

https://github.com/hangwin/mcp-chrome
generic

mcp-chrome/app/native-server/src/server/index.ts at v1.0.0 · hangwin/mcp-chrome · GitHub

https://github.com/hangwin/mcp-chrome/blob/v1.0.0/app/native-server/src/server/index.ts
generic

CORS origin bypass in native-server HTTP API allows any website to drive the MCP server (CSWSH) · Issue #384 · hangwin/mcp-chrome · GitHub

https://github.com/hangwin/mcp-chrome/issues/384

Vendor Advisories for CVE-2026-102878(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 21× in last 7d / 21× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-10-04 04:00 UTCGHSA enrichment
  2. 2026-10-03 16:15 UTCEG score recompute
  3. 2026-10-03 16:15 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 04:31 UTCGHSA enrichment
  6. 2026-10-02 16:46 UTCEG score recompute
  7. 2026-10-02 16:46 UTCGHSA enrichment
  8. 2026-10-02 05:01 UTCEG score recompute
  9. 2026-10-02 05:01 UTCGHSA enrichment
  10. 2026-10-01 19:49 UTCEPSS rescore
  11. 2026-10-01 17:15 UTCGHSA enrichment
  12. 2026-10-01 05:30 UTCGHSA enrichment
  13. 2026-09-30 17:45 UTCEG score recompute
  14. 2026-09-30 17:45 UTCGHSA enrichment
  15. 2026-09-30 15:02 UTCEPSS rescore
  16. 2026-09-30 09:08 UTCEG score recompute
  17. 2026-09-30 09:08 UTCGHSA enrichment
  18. 2026-09-29 21:21 UTCEG score recompute
  19. 2026-09-29 20:22 UTCEG score recompute
  20. 2026-09-29 20:03 UTCEG score recompute
  21. 2026-09-29 20:03 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-102878?
CVE-2026-102878 is a high vulnerability published on September 29, 2026. mcp-chrome-bridge through 1.0.31 contains an origin validation error in the native-server HTTP API that allows attackers to bypass CORS restrictions. Attackers can craft malicious web pages that make cross-origin requests to the local server and invoke browser automation tools including script…
When was CVE-2026-102878 disclosed?
CVE-2026-102878 was first published on September 29, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-102878 actively exploited?
CVE-2026-102878 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (13th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-102878?
CVE-2026-102878 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-102878?
No fix for CVE-2026-102878 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 vendor advisories EchelonGraph has for CVE-2026-102878 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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