How severe is CVE-1999-1055?

CVE-1999-1055 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-1999-1055 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1055?

CVE-1999-1055 affects Microsoft Excel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-1055?

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

When was CVE-1999-1055 published?

CVE-1999-1055 was published on 1999-12-31 and last updated on 2026-06-16.

CVE-1999-1055

CVE-1999-1055 is a high-severity vulnerability in Microsoft Excel with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Excel
Published: 1999-12-31
Last modified: 2026-06-16

Description

Microsoft Excel 97 does not warn the user before executing worksheet functions, which could allow attackers to execute arbitrary commands by using the CALL function to execute a malicious DLL, aka the Excel "CALL Vulnerability."

Frequently asked questions

What is CVE-1999-1055?: Microsoft Excel 97 does not warn the user before executing worksheet functions, which could allow attackers to execute arbitrary commands by using the CALL function to execute a malicious DLL, aka the Excel "CALL Vulnerability."
How severe is CVE-1999-1055?: CVE-1999-1055 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-1999-1055 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1055?: CVE-1999-1055 affects Microsoft Excel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-1055?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-1999-1055 published?: CVE-1999-1055 was published on 1999-12-31 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:microsoft:excel:97:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Excel

CVE-2008-0081 — Critical (CVSS 9.8): Unspecified vulnerability in Microsoft Excel 2000 SP3 through 2003 SP2, Viewer 2003, and Office 2004 for Mac allows…
CVE-2015-6177 — Critical (CVSS 9.3): Microsoft Excel 2007 SP3, Office Compatibility Pack SP3, and Excel Viewer allow remote attackers to execute arbitrary…
CVE-2015-6122 — Critical (CVSS 9.3): Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel for Mac 2011, Office Compatibility Pack SP3, and Excel Viewer allow…
CVE-2015-6040 — Critical (CVSS 9.3): Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel for Mac 2011, Excel 2016 for Mac, Office Compatibility Pack SP3, and…
CVE-2015-6094 — Critical (CVSS 9.3): Microsoft Excel 2010 SP2, Excel 2013 SP1, Excel 2013 RT SP1, Excel 2016, Excel for Mac 2011, Excel 2016 for Mac, and…
CVE-2015-6038 — Critical (CVSS 9.3): Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel 2013 SP1, Excel 2013 RT SP1, Excel 2016, Excel for Mac 2011, Excel 2016…

All CVEs affecting Microsoft Excel →