Is CVE-2011-4539 being actively exploited?

CVE-2011-4539 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2011-4539?

CVE-2011-4539 has a CVSS 2.0 base score of 5.0 (MEDIUM).

CVE-2011-4539

MEDIUM · CVSS 5.0EPSS 15.2%EU EUVD

dhcpd in ISC DHCP 4.x before 4.2.3-P1 and 4.1-ESV before 4.1-ESV-R4 does not properly handle regular expressions in dhcpd.conf, which allows remote attackers to cause a denial of service (daemon crash) via a crafted request packet.

Key facts

CVSS score: 5.0 (v2.0)
Severity: MEDIUM
CVSS vector: AV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness (CWE): CWE-20
EPSS score: 15.2% (97th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2011-4465)
Published: December 8, 2011
NVD last modified: June 16, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2011-4465 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.

View on the EU Vulnerability Database

Affected products

canonical / ubuntu linux
canonical / ubuntu linux
debian / debian linux
debian / debian linux
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp
isc / dhcp

References

http://lists.fedoraproject.org/pipermail/package-announce/2011-December/070980.html(Mailing List, Third Party Advisory)
http://lists.fedoraproject.org/pipermail/package-announce/2012-January/071549.html(Mailing List, Third Party Advisory)
http://lists.opensuse.org/opensuse-updates/2011-12/msg00006.html(Mailing List, Third Party Advisory)
http://secunia.com/advisories/47153(Third Party Advisory)
http://secunia.com/advisories/47178(Third Party Advisory)
http://security.gentoo.org/glsa/glsa-201301-06.xml(Third Party Advisory)
http://www.debian.org/security/2012/dsa-2519(Third Party Advisory)
http://www.mandriva.com/security/advisories?name=MDVSA-2011:182(Third Party Advisory)
http://www.securityfocus.com/bid/50971(Third Party Advisory, VDB Entry)
http://www.securitytracker.com/id?1026393(Third Party Advisory, VDB Entry)
http://www.ubuntu.com/usn/USN-1309-1(Third Party Advisory)
https://exchange.xforce.ibmcloud.com/vulnerabilities/71680(Third Party Advisory, VDB Entry)
https://www.isc.org/software/dhcp/advisories/cve-2011-4539(Vendor Advisory)

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

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