Netskope Client Captive Portal WebView Persistence allowing SWG bypass issue
Summary
| CVE | CVE-2026-12254 |
|---|---|
| State | PUBLISHED |
| Assigner | Netskope |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-19 16:17:07 UTC |
| Updated | 2026-10-20 20:17:20 UTC |
| Description | Netskope is notified about a potential gap in its agent (NSClient) where a system with Netskope Client while connecting to an access point with Captive Portal switches to a Network which already has internet connectivity, the Captive Portal does not close. This allows the possibility of abuse via the Captive Portal using a rogue access point to either access malicious sites or exfiltrate data.The issue impacts all versions prior to R142 |
Risk And Classification
Primary CVSS: v4.0 6.4 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/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
EPSS: 0.002390000 probability, percentile 0.141030000 (date 2026-10-20)
Problem Types: CWE-613 | CWE-613 CWE-613 Insufficient session expiration
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.4 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 6.4 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Netskope Inc. | Netskope Client | affected 142 custom | Windows, MacOS |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.netskope.com/resources/netskope-resources/netskope-security-advisory-nskps... | [email protected] | www.netskope.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Loïc Croche (Independant security researcher) (en)
Additional Advisory Data
Solutions
CNA: Netskope has fixed the gap and released the patch as listed below: R142 and above R141 (141.1.7.2827 and above) R138 (138.1.15.2826 and above) R135 (135.1.7.2827 and above)