Exploited CVEs / Microsoft / CVE-2008-4250

CVE-2008-4250 (MS08-067)

Microsoft Windows Buffer Overflow Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2026-06-03 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Microsoft Security Update Guide (MSRC), linked below.

Risk summary

UnratedCISA KEV

CVSS v3 base

Not scored

EPSS exploit probability

Unrated

Severity

2026-05-20

Added to KEV

2026-06-03 (past due)

CISA due date

Actively exploited Microsoft Windows vulnerability, Microsoft bulletin MS08-067. Added to the CISA KEV catalog 2026-05-20.

Senserva AI read on CVE-2008-4250 CISA required action Official fix for CVE-2008-4250 Admin questions

Senserva AI Opinion for CVE-2008-4250

CVE-2008-4250 is the vulnerability patched by Microsoft bulletin MS08-067 (KB958644). The flaw lives in the Windows Server service, specifically a stack buffer overflow reached through the NetPathCanonicalize function while a crafted RPC request is being canonicalized. On Windows 2000, XP, and Server 2003 an attacker can hit it over RPC with no authentication and no user interaction, which is why Microsoft released it as an out-of-band patch in October 2008 and flagged it as potentially wormable. That prediction held: it was exploited in the wild by the Gimmiv.A trojan and then weaponized at scale by the Conficker worm, which spread over SMB port 445. What is new is that CISA added this specific CVE to the Known Exploited Vulnerabilities catalog on 2026-05-20, so it is being treated as active exploitation to act on now rather than a closed historical case. The realistic exposure today is not a fully patched fleet; it is legacy or unmanaged Windows 2000, XP, Server 2003, Vista, and Server 2008 hosts (embedded devices, isolated lab or OT machines, forgotten VMs) that still speak SMBv1/RPC on port 445 and never received KB958644. There is no confirmed ransomware association recorded for this entry, but unauthenticated remote code execution on the Server service is a full-system-compromise primitive.

Do this: Confirm the MS08-067 (KB958644) update is present on every Windows 2000, XP, Server 2003, Vista, and Server 2008 asset you own, including images, VMs, and OT or embedded systems that rarely reboot. For any host too old to patch, block inbound TCP 445 and 139 at the host and network boundary, disable SMBv1, and restrict the Server service to trusted segments; ideally retire or isolate the machine. Hunt for the exploit path by watching for anomalous RPC traffic to the srvsvc named pipe and unexpected SMB scanning of port 445 internally, which is the signature of self-propagating use. Treat the CISA KEV due date as your deadline given the 2026-05-20 catalog addition.

Key sources

Microsoft Security Bulletin MS08-067 - Critical: Vulnerability in Server Service Could Allow Remote Code Execution (958644): Primary vendor advisory that names the fix (KB958644), the affected Windows versions, and the unauthenticated wormable RPC nature of the flaw.
CISA Adds Seven Known Exploited Vulnerabilities to Catalog (2026-05-20): Primary authority confirming the current KEV listing and the specific 2026-05-20 date that makes this an act-now item.
CVE-2008-4250 Detail (Tenable): Respected analyst source that ties the CVE to path canonicalization and to in-the-wild exploitation by Gimmiv.A, useful for scoping affected editions.

AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2008-4250

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2008-4250, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2008-4250.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2008-4250: Microsoft Windows Buffer Overflow Vulnerability
- Affected: Microsoft Windows
- Severity: Unrated
- Added to CISA KEV: 2026-05-20; federal remediation due 2026-06-03
- Ransomware-linked: no
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

The fix ships from the vendor: Microsoft Security Update Guide (MSRC).

Do this now: Federal remediation deadline 2026-06-03; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 19, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2008-4250

Published: 2026-05-20
Last revised: 2026-05-20
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

2026-05-20 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 9.8; CVSS 9.8 to 0.0; EPSS first scored at 0.0%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2026-06-03 (past due).

Official fix for CVE-2008-4250

The authoritative fix and affected-version list are published by the vendor. Find the Windows advisory on Microsoft Security Update Guide (MSRC).

Microsoft Security Update Guide (MSRC)CISA KEV entry

Common questions about CVE-2008-4250

Is CVE-2008-4250 actively exploited?

Yes. CVE-2008-4250 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2026-05-20, which means exploitation in the wild has been confirmed, not predicted.

What is the CISA deadline and required action for CVE-2008-4250?

CISA set the federal (BOD 22-01) remediation due date at 2026-06-03, which has passed; treat any unremediated system as overdue.

What fixes CVE-2008-4250?

The authoritative fix is in the vendor advisory: see Microsoft Security Update Guide (MSRC) for the patched Windows versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2008-4250?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2008-4250's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited Microsoft CVEs: CVE-2009-1537 CVE-2010-0249 CVE-2010-0806 CVE-2026-41091 CVE-2026-45498 CVE-2026-33825 CVE-2009-0238 CVE-2012-1854
All Microsoft exploited CVEs on one page: Microsoft vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog Microsoft MSRC FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.