How severe is CVE-1999-0861?

CVE-1999-0861 has a CVSS 2.0 base score of 2.6, rated low severity.

Is CVE-1999-0861 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0861?

CVE-1999-0861 primarily affects Microsoft Commercial Internet System. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-0861?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-1999-0861 published?

CVE-1999-0861 was published on 1999-08-11 and last updated on 2026-06-16.

CVE-1999-0861

CVE-1999-0861 is a low-severity vulnerability in Microsoft Commercial Internet System with a CVSS 2.0 base score of 2.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.

Key facts

Severity: Low (CVSS 2.0 base score 2.6)
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Microsoft Commercial Internet System
Published: 1999-08-11
Last modified: 2026-06-16

Description

Race condition in the SSL ISAPI filter in IIS and other servers may leak information in plaintext.

Frequently asked questions

What is CVE-1999-0861?: Race condition in the SSL ISAPI filter in IIS and other servers may leak information in plaintext.
How severe is CVE-1999-0861?: CVE-1999-0861 has a CVSS 2.0 base score of 2.6, rated low severity.
Is CVE-1999-0861 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0861?: CVE-1999-0861 primarily affects Microsoft Commercial Internet System. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-0861?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-1999-0861 published?: CVE-1999-0861 was published on 1999-08-11 and last updated on 2026-06-16.

References

Affected products (5)

cpe:2.3:a:microsoft:commercial_internet_system:2.0:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:commercial_internet_system:2.5:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:internet_information_server:4.0:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:site_server:3.0:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:site_server_commerce:3.0:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Commercial Internet System

CVE-2000-0053 — High (CVSS 7.5): Microsoft Commercial Internet System (MCIS) IMAP server allows remote attackers to cause a denial of service via a…
CVE-1999-0777 — High (CVSS 7.5): IIS FTP servers may allow a remote attacker to read or delete files on the server, even if they have "No Access"…
CVE-2000-0246 — Medium (CVSS 5.0): IIS 4.0 and 5.0 does not properly perform ISAPI extension processing if a virtual directory is mapped to a UNC share,…
CVE-1999-0910 — Medium (CVSS 5.0): Microsoft Site Server and Commercial Internet System (MCIS) do not set an expiration for a cookie, which could then be…
CVE-1999-0867 — Medium (CVSS 5.0): Denial of service in IIS 4.0 via a flood of HTTP requests with malformed headers.

All CVEs affecting Microsoft Commercial Internet System →

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CVE-2014-0703 — Critical (CVSS 10.0): Cisco Wireless LAN Controller (WLC) devices 7.4 before 7.4.110.0 distribute Aironet IOS software with a race condition…
CVE-2010-1228 — Critical (CVSS 10.0): Multiple race conditions in the sandbox infrastructure in Google Chrome before 4.1.249.1036 have unspecified impact and…
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CVE-2026-46137 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: fix potential…

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