CVE-2025-40601
Published: May 13, 2026
Official Description
A Stack-based buffer overflow vulnerability in the SonicOS SSLVPN service allows a remote unauthenticated attacker to cause Denial of Service (DoS), which could cause an impacted firewall to crash.
Risk Analysis
This stack-based buffer overflow vulnerability in the SonicOS SSLVPN service allows a remote unauthenticated attacker to cause a denial of service. This could lead to an impacted firewall crashing, disrupting network operations. Its inclusion in CISA's KEV confirms active exploitation, making it an urgent concern.
This vulnerability is remotely exploitable. Active exploitation has been observed in the wild, as indicated by its 'in_the_wild' exploit status and inclusion in CISA's KEV.
To mitigate this, apply the latest security patches and firmware updates for SonicOS SSLVPN. Ensure that all network devices are regularly updated and configured to prevent buffer overflow exploits.
Technical Analysis
CVE-2025-40601 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2025-40601 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Exploit & PoC Resources
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2025-40601 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1