Quantum Security Gateway
CVE-2026-50752: Certificate Validation Bypass in VPN Site-to-Site Connections Using IKEv1
A weakness in the certificate validation logic of the deprecated IKEv1 key exchange may allow an unauthenticated attacker positioned as a man-in-the-middle to bypass certificate validation in VPN site-to-site connections that use certificate-based authentication.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Quantum Security Gateway R82.10 with Jumbo Hotfix Take 19 or below | See the advisory |
| Quantum Security Gateway R82 with Jumbo Hotfix Take 103 or below | See the advisory |
| Quantum Security Gateway R81.20 with Jumbo Hotfix Take 141 or below | See the advisory |
| Quantum Security Gateway R81.10, R81, and R80 | See the advisory |
| Spark Firewalls R80.20 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A weakness in the certificate validation logic of the deprecated IKEv1 key exchange may allow an unauthenticated attacker positioned as a man-in-the-middle to bypass certificate validation in VPN site-to-site connections that use certificate-based authentication. Successful exploitation could allow interception or modification of traffic traversing the VPN tunnel.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 10 Oct 2026.