CVE-2026-15409Known ransomware useCRITICAL · 10.0Patch first

SonicWall SMA1000 Appliances Server-Side Request Forgery Vulnerability

CVE-2026-15409 is a security vulnerability in SonicWall SMA1000 Appliances, added to CISA KEV on July 14, 2026. Patch order: first of four. Known ransomware use: yes.

Added to CISA KEV · Updated · SonicWall SMA1000 Appliances

What is CVE-2026-15409?

SonicWall SMA1000 Appliances contain a server-side request forgery vulnerability that could allow a remote unauthenticated attacker to potentially cause the appliance to make requests to unintended location.

Known to be used in ransomware campaigns. Active threat actors have chained this vulnerability into ransomware operations — treat patching as a same-week priority, not a "next maintenance window" task. The fix is the same one below; the urgency is higher.

Who is affected by CVE-2026-15409?

Affects anyone whose network is fronted by a SonicWall firewall or SSL VPN. The device sits at the edge between your office and the internet and authenticates remote workers — exploitation typically means an attacker reaches inside without needing a user credential.

What should I do about CVE-2026-15409?

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Request a free review.

Insurance readiness

Your insurer will ask if this is patched.

Unpatched entries on CISA's Known Exploited Vulnerabilities list are exactly what cyber-insurance carrier questionnaires probe for, and knowing which controls they check is how you keep a renewal from stalling.

Get the free carrier questionnaire →

Severity

CVSS base score: 10.0 — CRITICAL

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weakness classification: CWE-918

CVSS, severity, and CWE data from the National Vulnerability Database (NVD). This product uses data from the NVD API but is not endorsed or certified by the NVD.

CISA due date

CISA's listed due date: July 17, 2026.

Federal civilian agencies work under CISA's Binding Operational Directive 26-04, which replaced BOD 22-01 on June 10, 2026. It sets the deadline for each affected system by:

  • How exposed that system is to the internet
  • Whether the attack can be automated
  • How much control it gives an attacker

Its table gives catalogued vulnerabilities 3 or 14 days.

None of this binds a private business, but treat the date as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).

EPSS

EPSS score: 6.8% — higher than 94% of all scored CVEs.

EPSS estimates the probability of exploitation activity in the next 30 days. Every entry on this site is already confirmed exploited, so read it as relative urgency among the things you still have open, not as permission to wait.

Score dated 2026-10-14, from the FIRST.org Exploit Prediction Scoring System.

Source

This entry comes from CISA's Known Exploited Vulnerabilities catalog, public US-Government data we pull daily. The plain-language framing and the what-to-do guidance above are ours. View the original entry on cisa.gov.

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Watching: SonicWall