Which products and versions are affected by CVE-1999-0918?

Affected: Windows 2000 (Microsoft); Windows 95 (Microsoft); Windows 98 (Microsoft), among others. The full list is in the CVE brief.

Is CVE-1999-0918 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-1999-0918 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-1999-0918?

Public exploit code is available.

Is there a fix for CVE-1999-0918?

No fixed version is listed yet; check the vendor advisory for mitigations.

How urgently should CVE-1999-0918 be patched?

Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Request A Demo

WatchlistHigh

CVE-1999-0918Windows 2000 Vulnerability

Denial of service in various Windows systems via malformed, fragmented IGMP packets.

Published Jul 3, 1999 · Updated Apr 15, 2026

Key Facts

Patch immediately

CVE-1999-0918 is a high-severity vulnerability (CVSS 7.8 v2) affecting Windows 2000 (Microsoft), Windows 95 (Microsoft), Windows 98 (Microsoft) and 1 more product.
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 26% probability of exploitation in the next 30 days.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Scores

CVSS v2

7.8

AV:N/AC:L/Au:N/C:N/I:N/A:C

EPSS (30-day exploit likelihood)

26%

Higher than 97.9% of all scored CVEs

Exploit maturity

Proof of concept

ATLAS score

41/100

Publication score, see How it works

Exploitation Verdict

KEV listed

Not listed

Federal due date

None

No federal due date

Ransomware use

Not reported

Attributed actors

None named

Exploit & Defence Guidance

Exploit maturity

Proof of concept

Public exploit code

Proof-of-concept links

In-the-wild evidence

Reports of active use

Description

Denial of service in various Windows systems via malformed, fragmented IGMP packets.

Affected Products

9 affected entries in total

Product	Affected versions	Fixed in
Windows 2000Microsoft	See advisory	n/a
Windows 95Microsoft	See advisory	n/a
Windows 98Microsoft	See advisory	n/a
Windows NtMicrosoft	4.0, 4.0-sp1, 4.0-sp2, 4.0-sp3, 4.0-sp4, 4.0-sp5	n/a

Timeline

Publicly disclosed
Jul 3, 1999
Last updated
Apr 15, 2026

Weakness Type

CWE-20 Improper Input Validation

References

1 more references in the full CVE brief

FAQ

Common Questions.

Denial of service in various Windows systems via malformed, fragmented IGMP packets.
Affected: Windows 2000 (Microsoft); Windows 95 (Microsoft); Windows 98 (Microsoft), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Is CVE-1999-0918 On Your Attack Surface?

Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.