Context isolation bypass via Function.prototype.bind hijack
Published Aug 5, 2026 · Updated Aug 5, 2026
Context isolation bypass in affected Electron releases allows remote attackers to access isolated preload-world capabilities. The Promise bridge invokes an attacker-replaced Function.prototype.bind from the untrusted main world, exposing an isolated-world function as the bind receiver. Apps are exposed only when contextBridge publishes Promise-returning functions to windows that load untrusted content; an unsandboxed renderer or enabled nodeIntegration extends the captured preload authority to Node.js access.
Summary
What happened
Context isolation bypass in affected Electron releases allows remote attackers to access isolated preload-world capabilities. The Promise bridge invokes an attacker-replaced Function.prototype.bind from the untrusted main world, exposing an isolated-world function as the bind receiver. Apps are exposed only when contextBridge publishes Promise-returning functions to windows that load untrusted content; an unsandboxed renderer or enabled nodeIntegration extends the captured preload authority to Node.js access.
The record
- CVE
- CVE-2026-70601
- Published
- Aug 5, 2026
- Updated
- Aug 5, 2026
- Vendor
- Electron
- Product
- Electron
- Classifications
- CWE-693, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 5, 2026CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 39.8.9
- Affected versionversion=>= 40.0.0-alpha.1, < 40.9.2
- Affected versionversion=>= 41.0.0-alpha.1, < 41.2.2
- Affected versionversion=>= 42.0.0-alpha.1, < 42.0.0-beta.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo