Known exploited · Microsoft

CVE-2008-4250: Microsoft Windows Buffer Overflow Vulnerability

What it is

Microsoft Windows contains a buffer overflow vulnerability in the Windows Server Service that allows remote attackers to execute arbitrary code via a crafted RPC request that triggers an overflow during path canonicalization.

Added May 20, 2026Due June 3, 2026CISA KEV catalog 2026.10.01

Vendor
Microsoft
Product
Windows
Added to KEV
May 20, 2026
CISA due date
June 3, 2026
Ransomware use
Unknown

What CISA requires

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Forensic triage

No

What to do now

  1. Find every instance of Windows you run, including the forgotten ones, and check its version against the vendor advisory.
  2. Apply the vendor's fix or mitigation, before June 3, 2026 if you are bound by CISA's deadline, sooner if it faces the internet.
  3. Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
  4. Until every instance is patched, block the attack at the edge: a WAF in blocking mode stops PHP and Node.js code injection payloads.

References

CVE-2008-4250 in the National Vulnerability Database

The Dome

Block it at the edge while you patch

The Dome's WAF runs the OWASP Core Rule Set in blocking mode and stops PHP and Node.js code injection payloads before they reach your application.

See the Dome

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Train the engineers who fix it

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Source: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.