CVE-2026-70606
Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
- Record
CVE-2026-70606- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
EUVDEUVD-2026-53445
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
- Record
EUVD-2026-53445- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-r4w5-6pfg-jxp5
Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
Impact
When a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions.
Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. Apps that set an explicit session, or that do not isolate content across sessions, are not affected.
Workarounds
Set ProtocolResponse.session explicitly so the request uses the intended session's cache.
Fixed Versions
43.0.042.5.141.9.140.10.6
For more information
If you have any questions or comments about this advisory, email Electron at [email protected]
- Record
GHSA-r4w5-6pfg-jxp5- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
NVD
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
- Record
CVE-2026-70606- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
OSV
Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
- Record
CVE-2026-70606- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
OSVGHSA-r4w5-6pfg-jxp5
Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
Impact
When a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions.
Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. Apps that set an explicit session, or that do not isolate content across sessions, are not affected.
Workarounds
Set ProtocolResponse.session explicitly so the request uses the intended session's cache.
Fixed Versions
43.0.042.5.141.9.140.10.6
For more information
If you have any questions or comments about this advisory, email Electron at [email protected]
- Record
GHSA-r4w5-6pfg-jxp5- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-70606 is a medium vulnerability (CVSS 5.9) in Electron, published August 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 17th percentile. Fixed in electron 43.0.0.