Vulnerability · CVE-2025-40600
SonicWall SonicOS Use of Externally-Controlled Format String
Published May 10, 2026 · corrected/updated May 10, 2026 · SonicWall SonicOS · evidence confidence very high
Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2025-40600 is a unknown public vulnerability record for SonicWall SonicOS. CISA lists it as known exploited. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether SonicWall SonicOS is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: SonicWall SonicOS. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: EPSS 0.9%. CISA lists it as known exploited. Sources contributing to this record: cve_org, epss, vulncheck_kev. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Confirmed in CISA KEV since May 10, 2026. Listed in CISA KEV and VulnCheck KEV.
Patch and remediation
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
May 10, 2026 · VulnCheck KEV
Detected
Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.
May 10, 2026 · CISA KEV
Known exploited
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected
- vendor SonicWall SonicOSversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2025-40600
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-40600
30-day exploitation probability 0.9%
first.org - VulnCheck KEVConfirmed exploitationCVE-2025-40600
Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.
vulncheck.com