Is CVE-2009-4086 being actively exploited?

CVE-2009-4086 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2009-4086?

CVE-2009-4086 has a CVSS 2.0 base score of 5.0 (MEDIUM).

CVE-2009-4086

MEDIUM · CVSS 5.0EPSS 4.8%EU EUVD

CRLF injection vulnerability in Xerver HTTP Server 4.31 and 4.32 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via certain byte sequences at the end of a URL. NOTE: some of these details are obtained from third party information.

Key facts

CVSS score: 5.0 (v2.0)
Severity: MEDIUM
CVSS vector: AV:N/AC:L/Au:N/C:N/I:P/A:N
Weakness (CWE): CWE-20
EPSS score: 4.8% (92th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2009-4057)
Published: November 29, 2009
NVD last modified: June 16, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2009-4057 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.

View on the EU Vulnerability Database

Affected products

javascript / xerver http server
javascript / xerver http server

References

http://packetstormsecurity.org/0911-exploits/xerver-split.txt(Exploit)
http://secunia.com/advisories/36681(Vendor Advisory)
http://www.securityfocus.com/bid/37064(Exploit)
https://exchange.xforce.ibmcloud.com/vulnerabilities/54356

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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