How severe is CVE-2000-0258?

CVE-2000-0258 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2000-0258 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2000-0258?

CVE-2000-0258 primarily affects Microsoft Internet Information Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2000-0258?

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-2000-0258 published?

CVE-2000-0258 was published on 2000-04-12 and last updated on 2026-06-16.

CVE-2000-0258

CVE-2000-0258 is a high-severity vulnerability in Microsoft Internet Information Server with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 20% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 20% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Microsoft Internet Information Server
Published: 2000-04-12
Last modified: 2026-06-16

Description

IIS 4.0 and 5.0 allows remote attackers to cause a denial of service by sending many URLs with a large number of escaped characters, aka the "Myriad Escaped Characters" Vulnerability.

Frequently asked questions

What is CVE-2000-0258?: IIS 4.0 and 5.0 allows remote attackers to cause a denial of service by sending many URLs with a large number of escaped characters, aka the "Myriad Escaped Characters" Vulnerability.
How severe is CVE-2000-0258?: CVE-2000-0258 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2000-0258 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2000-0258?: CVE-2000-0258 primarily affects Microsoft Internet Information Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2000-0258?: 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-2000-0258 published?: CVE-2000-0258 was published on 2000-04-12 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:microsoft:internet_information_server:4.0:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:internet_information_services:5.0:*:*:*:*:*:*:*

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