vulnerability / NVI-00015342 / Revision 3
Electron: contextBridge object copy honors prototype setters
GitHub lists this reviewed advisory for electron, electron, electron, electron. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5.4 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.564%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.4696. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
electron
source listed< 39.8.9
### Impact Objects copied across the `contextBridge` boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled. Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks. Apps that only accept primitive arguments, or that validate object arguments, are not affected. ### Workarounds Validate objects received from untrusted content with own-property checks (`Object.hasOwn`), or copy them onto a null-prototype object before use. ### Fixed Versions * `42.0.0-beta.4` * `41.2.2` * `40.9.2` * `39.8.9` ### For more information If you have any questions or comments about this advisory, email Electron at security@electronjs.org
electron
source listed>= 40.0.0-alpha.1, < 40.9.2
### Impact Objects copied across the `contextBridge` boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled. Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks. Apps that only accept primitive arguments, or that validate object arguments, are not affected. ### Workarounds Validate objects received from untrusted content with own-property checks (`Object.hasOwn`), or copy them onto a null-prototype object before use. ### Fixed Versions * `42.0.0-beta.4` * `41.2.2` * `40.9.2` * `39.8.9` ### For more information If you have any questions or comments about this advisory, email Electron at security@electronjs.org
electron
source listed>= 41.0.0-alpha.1, < 41.2.2
### Impact Objects copied across the `contextBridge` boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled. Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks. Apps that only accept primitive arguments, or that validate object arguments, are not affected. ### Workarounds Validate objects received from untrusted content with own-property checks (`Object.hasOwn`), or copy them onto a null-prototype object before use. ### Fixed Versions * `42.0.0-beta.4` * `41.2.2` * `40.9.2` * `39.8.9` ### For more information If you have any questions or comments about this advisory, email Electron at security@electronjs.org
electron
source listed>= 42.0.0-alpha.1, < 42.0.0-beta.4
### Impact Objects copied across the `contextBridge` boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled. Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks. Apps that only accept primitive arguments, or that validate object arguments, are not affected. ### Workarounds Validate objects received from untrusted content with own-property checks (`Object.hasOwn`), or copy them onto a null-prototype object before use. ### Fixed Versions * `42.0.0-beta.4` * `41.2.2` * `40.9.2` * `39.8.9` ### For more information If you have any questions or comments about this advisory, email Electron at security@electronjs.org
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-ff2p-hmqr-hxm4 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-70610 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.