How severe is CVE-2016-2774?

CVE-2016-2774 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2016-2774 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 74% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-2774?

CVE-2016-2774 primarily affects Isc Dhcp. In total, 95 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-2774?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2016-2774 published?

CVE-2016-2774 was published on 2016-03-09 and last updated on 2026-06-17.

CVE-2016-2774

CVE-2016-2774 is a medium-severity vulnerability in Isc Dhcp with a CVSS 3.x base score of 5.9. Its EPSS exploit-prediction score of 74% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 7.1
EPSS exploit prediction: 74% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Isc Dhcp
Published: 2016-03-09
Last modified: 2026-06-17

Description

ISC DHCP 4.1.x before 4.1-ESV-R13 and 4.2.x and 4.3.x before 4.3.4 does not restrict the number of concurrent TCP sessions, which allows remote attackers to cause a denial of service (INSIST assertion failure or request-processing outage) by establishing many sessions.

Frequently asked questions

What is CVE-2016-2774?: ISC DHCP 4.1.x before 4.1-ESV-R13 and 4.2.x and 4.3.x before 4.3.4 does not restrict the number of concurrent TCP sessions, which allows remote attackers to cause a denial of service (INSIST assertion failure or request-processing outage) by establishing many sessions.
How severe is CVE-2016-2774?: CVE-2016-2774 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2016-2774 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 74% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-2774?: CVE-2016-2774 primarily affects Isc Dhcp. In total, 95 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-2774?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-2774 published?: CVE-2016-2774 was published on 2016-03-09 and last updated on 2026-06-17.

References

Affected products (95)

cpe:2.3:a:isc:dhcp:4.1-esv:-:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r10:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r10_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r11_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r11_rc1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r11_rc2:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r12:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r12_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r2:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r3:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r3_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r4:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r5:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r5_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r5_rc1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r5_rc2:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r6:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r7:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r8:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r8_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r8_rc1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r9:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r9_b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:r9_rc1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1-esv:rc1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.0:-:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.0:a1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.0:a2:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.0:b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.1:-:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.1:b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.1:b2:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.1:b3:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.1:p1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.1:rc1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.2:-:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.2:b1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.2:p1:*:*:*:*:*:*
cpe:2.3:a:isc:dhcp:4.1.2:rc1:*:*:*:*:*:*

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CVE-2011-2749 — High (CVSS 7.8): The server in ISC DHCP 3.x and 4.x before 4.2.2, 3.1-ESV before 3.1-ESV-R3, and 4.1-ESV before 4.1-ESV-R3 allows remote…
CVE-2011-2748 — High (CVSS 7.8): The server in ISC DHCP 3.x and 4.x before 4.2.2, 3.1-ESV before 3.1-ESV-R3, and 4.1-ESV before 4.1-ESV-R3 allows remote…
CVE-2011-0413 — High (CVSS 7.8): The DHCPv6 server in ISC DHCP 4.0.x and 4.1.x before 4.1.2-P1, 4.0-ESV and 4.1-ESV before 4.1-ESV-R1, and 4.2.x before…
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