CVE-2026-70610 — Electron: contextBridge object copy honors prototype setters
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.4, 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, while apps that only accept primitive arguments or validate object arguments are not affected. This issue is fixed in 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.4.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.6% (30-day exploitation probability)+7
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented mitigation — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Electron Electron, Electronjs Electron).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Electron | Electron | version < 39.8.9version >= 40.0.0-alpha.1, < 40.9.2version >= 41.0.0-alpha.1, < 41.2.2version >= 42.0.0-alpha.1, < 42.0.0-beta.4 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Electronjs | Electron |
< 39.8.9≥ 40.0.0 and < 40.9.2≥ 41.0.0 and < 41.2.2version 42.0.0-alpha1version 42.0.0-alpha2version 42.0.0-alpha3version 42.0.0-alpha4version 42.0.0-alpha5 and 4 moreversion 42.0.0-alpha6version 42.0.0-beta1version 42.0.0-beta2version 42.0.0-beta3 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.4 | CVSS 3.1 | Medium | 2.2 | 2.7 | security-advisories@github.com via NIST National Vulnerability Database |
| 5.4 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.56%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · electron/electron
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.4
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
13 on the record
- github.com/electron/electron/security/advisories/GHSA-ff2p-hmqr-hxm4
- github.com/electron/electron/commit/17d5d26499cd279fab48f5f26527f8edc02a7713
- github.com/electron/electron/commit/5b699544cbbed51bedb7c60d75c8c42be5825737
- github.com/electron/electron/pull/51086
- github.com/electron/electron/commit/4ac50292d552fb510eb778392620c85308770a55
- github.com/electron/electron/commit/23a6efb714dec80e2cf45d3054d18d701162e4dd
- github.com/electron/electron/pull/51085
- github.com/electron/electron/pull/51083
- github.com/electron/electron/pull/51084
- github.com/electron/electron/releases/tag/v40.9.2
- github.com/electron/electron/releases/tag/v41.2.2
- github.com/electron/electron/releases/tag/v42.0.0-beta.4
- github.com/electron/electron/releases/tag/v39.8.9
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-102672 Electron: Local race condition in Squirrel.Mac update installation on macOS 2d
- High CVE-2026-102677 Electron: Sandboxed preload code cache can be poisoned by a compromised renderer 16d
- Critical CVE-2026-102676 Electron: <webview> can enable Node.js integration in Web Workers despite embedder restrictions 16d
- Medium CVE-2026-102673 Electron drops inherited HTML sandbox restrictions for popups opened through OpenURLFromTab 16d
- Medium CVE-2026-102674 Electron: Windows opened from a sandboxed top-level document do not inherit its sandbox restrictions 16d
- Medium CVE-2026-70612 Electron: Sandboxed iframes can launch external protocol handlers Aug 5, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-70610 is "Electron: contextBridge object copy honors prototype setters", rated Medium. It affects Electron (Electron); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. EPSS 0.56% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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