How severe is CVE-2009-0558?

CVE-2009-0558 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2009-0558 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 31% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0558?

CVE-2009-0558 primarily affects Microsoft Office. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0558?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2009-0558 published?

CVE-2009-0558 was published on 2009-06-10 and last updated on 2026-06-16.

CVE-2009-0558

CVE-2009-0558 is a critical-severity vulnerability in Microsoft Office with a CVSS 2.0 base score of 9.3. Its EPSS exploit-prediction score of 31% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-94.

Key facts

Severity: Critical (CVSS 2.0 base score 9.3)
EPSS exploit prediction: 31% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Microsoft Office
Published: 2009-06-10
Last modified: 2026-06-16

Description

Array index error in Excel in Microsoft Office 2000 SP3 and Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac, allows remote attackers to execute arbitrary code via a crafted Excel file with a malformed record object, aka "Array Indexing Memory Corruption Vulnerability."

Frequently asked questions

What is CVE-2009-0558?: Array index error in Excel in Microsoft Office 2000 SP3 and Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac, allows remote attackers to execute arbitrary code via a crafted Excel file with a malformed record object, aka "Array Indexing Memory Corruption Vulnerability."
How severe is CVE-2009-0558?: CVE-2009-0558 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2009-0558 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 31% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0558?: CVE-2009-0558 primarily affects Microsoft Office. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0558?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2009-0558 published?: CVE-2009-0558 was published on 2009-06-10 and last updated on 2026-06-16.

References

Affected products (16)

cpe:2.3:a:microsoft:office:2004:*:mac:*:*:*:*:*
cpe:2.3:a:microsoft:office:2008:*:mac:*:*:*:*:*
cpe:2.3:a:microsoft:office:xp:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_compatibility_pack_for_word_excel_ppt_2007:*:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_compatibility_pack_for_word_excel_ppt_2007:*:sp2:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_excel:2000:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_excel:2003:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_excel:2007:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_excel:2007:sp2:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_excel_viewer:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_excel_viewer:2003:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_sharepoint_server:2007:sp1:x32:*:*:*:*:*
cpe:2.3:a:microsoft:office_sharepoint_server:2007:sp1:x64:*:*:*:*:*
cpe:2.3:a:microsoft:office_sharepoint_server:2007:sp2:x32:*:*:*:*:*
cpe:2.3:a:microsoft:office_sharepoint_server:2007:sp2:x64:*:*:*:*:*
cpe:2.3:a:microsoft:open_xml_file_format_converter:*:*:mac:*:*:*:*:*

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