How severe is CVE-2015-1635?

CVE-2015-1635 has a CVSS 3.1 base score of 9.8 (CRITICAL). EPSS estimates a 100.0% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2015-1635: Microsoft HTTP.sys Remote Code Execution Vulnerability

CISA Known Exploited Vulnerabilities

Microsoft HTTP.sys Remote Code Execution Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2022-02-10

Remediation due

2022-08-10

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2015-1635

Description

HTTP.sys in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8, Windows 8.1, and Windows Server 2012 Gold and R2 allows remote attackers to execute arbitrary code via crafted HTTP requests, aka "HTTP.sys Remote Code Execution Vulnerability."

Severity

CVSS 3.1 · CISA9.8 CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impacttotal

Exploitation Context

as of October 17, 2026

All KEV statistics→

CISA added CVE-2015-1635 to the KEV catalog 2,494 days after its CVE record was published.
It is one of 391 Microsoft entries in the CISA KEV catalog, and one of 166 added in 2022.
Its current EPSS score (100.0%) is higher than that of 97% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
-	-	n/a

References

7 Links

Vendor advisories

MS15-034

Exploits & PoCs

Vulnerability databases

Other references

http://packetstormsecurity.com/files/131463/Microsoft-Windows-HTTP.sys-Proof-Of-Concept.html

Record Details

Published

2015-04-14

Last updated

2025-10-22

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.