CVE-2025-40600 Denial of service in SonicOS

What is CVE-2025-40600?

CVE-2025-40600 is a critical denial of service vulnerability in Sonicwall Sonicos, published on 29 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.

Weakness: CWE-134

Which versions are affected by CVE-2025-40600?

It affects 1 product.

Products include Sonicwall Sonicos.

How do I fix CVE-2025-40600?

No fix has been published for CVE-2025-40600 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-40600 being exploited?

There is no known exploitation of CVE-2025-40600 in the wild and no public exploit code.

Other vulnerabilities in Sonicwall Sonicos

• CVE-2020-5135 SonicWall SonicOS Buffer Overflow Exploited Critical 9.8
• CVE-2024-40766 SonicWall SonicOS Improper Access Control Exploited Critical 9.3
• CVE-2024-53704 SonicWall SonicOS SSLVPN Improper Authentication Exploited High 8.2
• CVE-2024-22394 Auth bypass in SonicOS Critical 9.8
• CVE-2022-22274 Memory corruption in SonicOS Critical 9.8

All Sonicwall Sonicos vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-h43f-rh6w-3w65.