CVE-2007-0671: Microsoft Office Excel Remote Code Execution Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Microsoft Office. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-08-12, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-09-02; treat that as the outer limit, not the target.
• EPSS 43.2%, percentile 99: FIRST’s model estimates a 43.2% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.

What it is

Unspecified vulnerability in Microsoft Excel 2000, XP, 2003, and 2004 for Mac, and possibly other Office products, allows remote user-assisted attackers to execute arbitrary code via unknown attack vectors, as demonstrated by Exploit-MSExcel.h in targeted zero-day attacks.

CISA’s summary

Microsoft Office Excel contains a remote code execution vulnerability that can be exploited when a specially crafted Excel file is opened. This malicious file could be delivered as an email attachment or hosted on a malicious website. An attacker could leverage this vulnerability by creating a specially crafted Excel file, which, when opened, allowing an attacker to execute remote code on the affected system.

Product: Microsoft Office · Assigned by: microsoft · Published: 2007-02-03

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: required (a user must click/open something)
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2025-08-12; federal due date 2025-09-02. Known ransomware use: Unknown.
• CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
• CISA SSVC assessment: exploitation active, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 43.24% probability of exploitation activity in the next 30 days; percentile 99.

Timeline

• 2007-02-03 — CVE record published by microsoft
• 2025-08-12 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2025-09-02 — CISA remediation deadline for US federal agencies
• 2026-01-12 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. MS07-015 docs.microsoft.com
2. Listed in CISA KEV notes (learn.microsoft.com) learn.microsoft.com

Vulnerability records

1. CVE.org record CVE-2007-0671 cve.org
2. NVD entry CVE-2007-0671 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

1. ADV-2007-0463 vupen.com
2. oval:org.mitre.oval:def:301 oval.cisecurity.org
3. 31901 osvdb.org
4. microsoft.com microsoft.com
5. VU#613740 kb.cert.org
6. 1017584 securitytracker.com
7. avertlabs.com avertlabs.com
8. 24008 secunia.com
9. TA07-044A us-cert.gov
10. office-unspecified-code-execution(32178) exchange.xforce.ibmcloud.com
11. vil.nai.com vil.nai.com
12. 22383 securityfocus.com

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