capacitor-updater - End-to-End Encryption Bypass via Private Key Distribution
Summary
| CVE | CVE-2026-56254 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-10 15:16:41 UTC |
| Updated | 2026-07-10 16:16:33 UTC |
| Description | In @capgo/capacitor-updater (Cap-go/capgo) before 12.128.2, the end-to-end encryption scheme distributes the private key to each device that downloads the app. Because the public key can be derived from the private key, an attacker performing a man-in-the-middle attack or compromising the Capgo server can create a validly signed update bundle and cause devices to install an update not produced by the original app maker. |
Risk And Classification
Primary CVSS: v4.0 8.3 HIGH from [email protected]
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-320 | CWE-320 Key Management Errors
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.3 | HIGH | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.3 | HIGH | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Secondary | 7 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L |
| 3.1 | CNA | CVSS | 7 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
HighAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
HighAvailability
LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Capacitor-updater | Capacitor-updater | affected 12.128.2 semver | Not specified |
| CNA | Capacitor-updater | Capacitor-updater | unaffected 12.128.2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.vulncheck.com/advisories/capacitor-updater-end-to-end-encryption-bypass-via... | [email protected] | www.vulncheck.com | |
| github.com/Cap-go/capgo/security/advisories/GHSA-j2f4-4pfc-p8rx | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.