Ransomware

Check Point VPN Zero-Day Exploited in Qilin Ransomware Attacks

The authentication bypass vulnerability allows attackers to establish VPN connections without a valid password.

Ionut Arghire

Published

4 days ago

Check Point

Check Point on Monday warned that a critical-severity authentication bypass vulnerability affecting its VPN and firewall products has been exploited in the wild as a zero-day.

Tracked as CVE-2026-50751 (CVSS score of 9.3), the security defect is described as a logic flow weakness in the validation process of Remote Access and Mobile Access certificates.

It exists in the deprecated IKEv1 key exchange and allows remote attackers to establish VPN sessions without a valid password.

According to Check Point, the vulnerability has been exploited in the wild since May 7, with activity surrounding it increasing in early June.

“To date, the observed exploitation has been limited to a few dozen targeted organizations globally,” the company notes in its advisory.

Check Point also says that at least one attack was confirmed to have been mounted by a Qilin ransomware affiliate.

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“Based on the post-exploitation activity we observed, we assess with medium confidence that the actor behind the exploitation of CVE-2026-50751 is financially motivated and uses Qilin ransomware. We believe that this threat actor infrastructure is exploiting other VPN related vulnerabilities such as the ones published by Palo Alto, Fortinet and F5,” Check Point notes.

While investigating the security bug, the company identified a second issue in the IKEv1 key exchange’s certificate validation logic. Tracked as CVE-2026-50752, it allows attackers to mount man-in-the-middle attacks on VPN site-to-site connections, but has not been exploited in the wild.

Check Point has released hotfixes for the vulnerable appliances to address both CVEs, as well as indicators of compromise (IoCs) and mitigation guidance.

On Monday, the US cybersecurity agency CISA added CVE-2026-50751 to its Known Exploited Vulnerabilities (KEV) catalog, urging federal agencies to patch it by June 11.