CVE-2016-5426

PowerDNS (aka pdns) Authoritative Server before 3.4.10 allows remote attackers to cause a denial of service (backend CPU consumption) via a long qname.

Published: 2016-09-21 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-5426 is rated High Risk (67.1/100): CVSS High severity, with high exploitation likelihood (EPSS 36.97%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +3.15% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-5426

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-09 33.82% 36.97% +3.15%
2 2025-09-16 2.50% 33.82% +31.32%
3 2025-03-30 — 2.50% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-5426

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2016-5426

OS Trackers for CVE-2016-5426

vendor priority summary link
debian not yet assigned CVE-2016-5426 not yet assigned priority: Debian including 1 source packages (pdns), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-5426
ubuntu low CVE-2016-5426 low priority: Ubuntu including 1 source packages (pdns), 10 status rows across 10 suites (artful, bionic, cosmic, disco, precise, trusty, upstream, xenial, yakkety, zesty): not-affected 7, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2016-5426

Affected software / configurations for CVE-2016-5426

Vendor Product Version Raw CPE
powerdns authoritative <= 3.4.9 cpe:2.3:a:powerdns:authoritative:*:*:*:*:*:*:*:*

References for CVE-2016-5426

cvelogic Threat Intelligence