Electron: Extension tab APIs operate across session boundaries (CVE-2026-70602)
A vulnerability in Electron's extension tab and scripting APIs allowed extensions loaded in one session to access and manipulate windows in other sessions. This affects apps that load Chrome extensions via session.loadExtension and rely on session separation for isolation. The issue is fixed in Electron versions 39.8.8 and later.
AI Analysis
Technical Summary
Electron's extension tab and scripting APIs were not properly scoped to the extension's own session, enabling a malicious or compromised extension loaded in one session to navigate, script, and read windows belonging to different sessions. This breaks the intended isolation between sessions when multiple sessions are used to separate extensions from other content. Applications that do not load extensions or use only a single session are not affected. The vulnerability is tracked as CVE-2026-70602 and has a CVSS 3.1 base score of 6.6 (medium severity).
Potential Impact
A malicious or compromised extension can bypass session boundaries and access or manipulate windows in other sessions, potentially leading to unauthorized information disclosure and limited integrity impact. This affects applications that load Chrome extensions via session.loadExtension and rely on session isolation.
Mitigation Recommendations
A fix is available in Electron versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3. Users should upgrade to one of these versions or later. As a workaround, only load extensions from trusted sources and do not rely solely on session separation to contain extensions.
Electron: Extension tab APIs operate across session boundaries (CVE-2026-70602)
Description
A vulnerability in Electron's extension tab and scripting APIs allowed extensions loaded in one session to access and manipulate windows in other sessions. This affects apps that load Chrome extensions via session.loadExtension and rely on session separation for isolation. The issue is fixed in Electron versions 39.8.8 and later.
CVSS v3.1
Score 6.6medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Electron's extension tab and scripting APIs were not properly scoped to the extension's own session, enabling a malicious or compromised extension loaded in one session to navigate, script, and read windows belonging to different sessions. This breaks the intended isolation between sessions when multiple sessions are used to separate extensions from other content. Applications that do not load extensions or use only a single session are not affected. The vulnerability is tracked as CVE-2026-70602 and has a CVSS 3.1 base score of 6.6 (medium severity).
Potential Impact
A malicious or compromised extension can bypass session boundaries and access or manipulate windows in other sessions, potentially leading to unauthorized information disclosure and limited integrity impact. This affects applications that load Chrome extensions via session.loadExtension and rely on session isolation.
Mitigation Recommendations
A fix is available in Electron versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3. Users should upgrade to one of these versions or later. As a workaround, only load extensions from trusted sources and do not rely solely on session separation to contain extensions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-m55f-7gqj-fr98
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-70602"]
- Ecosystems
- ["npm"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a73851fbf8831d5394ef816
Added to database: 08/05/2026, 18:46:55 UTC
Last enriched: 08/05/2026, 23:17:58 UTC
Last updated: 08/05/2026, 23:17:58 UTC
Views: 2
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