CVE-2025-30187 | Denial of service via crafted DoH exchange in PowerDNS DNSdist

In some circumstances, when DNSdist is configured to use the nghttp2 library to process incoming DNS over HTTPS queries, an attacker might be able to cause a denial of service by crafting a DoH exchange that triggers an unbounded I/O read loop, causing an unexpected consumption of CPU resources.

Published: 2025-09-18 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-30187 is rated Low Risk (15.3/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.01%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

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-2025-30187

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 2025-09-18 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-30187

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.7 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.2 1.4 [email protected]

Weakness enumeration for CVE-2025-30187

OS Trackers for CVE-2025-30187

vendor priority summary link
alpine low CVE-2025-30187: 1 source package rows (dnsdist); 11 state rows across 2 repos (3.22-community, edge-community); fixed 1, open 10. https://security.alpinelinux.org/vuln/CVE-2025-30187
debian unimportant CVE-2025-30187 unimportant priority: Debian including 1 source packages (dnsdist), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-30187
suse medium CVE-2025-30187 severity moderate: SUSE including 3 source package names (dnsdist, dnsdist-1.9.11-150700.3.6.1, dnsdist-1.9.11-160000.1.1), 24 product×package rows across 23 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (23 product lines)): Known Not Affected 19, Fixed 4, First Fixed 1. https://www.suse.com/security/cve/CVE-2025-30187/
ubuntu medium CVE-2025-30187 medium priority: Ubuntu including 1 source packages (dnsdist), 8 status rows across 8 suites (bionic, focal, jammy, noble, plucky, questing, upstream, xenial): not-affected 6, released 2. https://ubuntu.com/security/CVE-2025-30187

Affected software / configurations for CVE-2025-30187

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-30187

cvelogic Threat Intelligence