🛡️ CVE-2025-20271
🟠 CVSS 8.6 — High ✅ No Known Exploit CWE-457 NVD
8.6
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition in the Cisco AnyConnect service on an affected device. This vulnerability is due to variable initialization errors when an SSL VPN session is established. An attacker could exploit this vulnerability by sending a sequence of crafted HTTPS requests to an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of all established SSL VPN sessions and forcing remote users to initiate a new VPN connection and re-authenticate. A sustained attack could prevent new SSL VPN connections from being established, effectively making the Cisco AnyConnect VPN service unavailable for all legitimate users.

Details

Severity HIGH
CVSS Score 8.6
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CWE CWE-457
Public Exploit ✅ No
Source NVD
Published 2025-06-18
Updated 2026-06-02
Modified 2026-04-15
Fix URL N/A

Affected Packages

Software From version Fixed in
unknown

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