# CVE-2026-42005: PowerDNS Authoritative Server denial of service in internal web server

Source: https://junglewise.ai/threats/cve-2026-42005-powerdns-authoritative-server-denial-of-service-in-internal-web  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-25. Updated: 2026-06-25  
License: CC BY 4.0 with a link back

CVE-2026-42005 · Severity: medium · CVSS 4.3 · Published 2026-06-25

A vulnerability in the PowerDNS Authoritative Server's internal web server could allow an authenticated user to crash the service. By sending a specially crafted web request, an attacker can cause the server to consume all available memory, leading to a denial of service. This component is disabled by default, which limits the risk to organizations that have manually enabled the internal web interface.

Technologies: [Powerdns Authoritative Server](https://junglewise.ai/threats/technologies/authoritative-server). Vendors: [Powerdns](https://junglewise.ai/threats/vendors/powerdns).

## Quick answers

**Is CVE-2026-42005 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42005 being exploited in the wild.

**How severe is CVE-2026-42005?** Medium severity, with a CVSS score of 4.3, published 25 June 2026.

**Which products and versions are affected?** Powerdns Authoritative Server 4.9.0 to 4.9.15, 5.0.0 to 5.0.5, 5.1.0 to 5.1.1.

**Is there a fix for CVE-2026-42005?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-42005 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-42005?** Check whether you run Powerdns Authoritative Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A resource exhaustion vulnerability exists in the YaHTTP component of the PowerDNS Authoritative Server. An authenticated attacker with access to the internal web server can send a malicious HTTP request that triggers unlimited memory allocation in 'ext/yahttp/yahttp/reqresp.cpp'. This results in a denial of service (DoS) as the system runs out of memory. The vulnerability affects versions 4.9.x, 5.0.x, and 5.1.x. Users are advised to upgrade to versions 4.9.16, 5.0.6, or 5.1.2 respectively. The internal web server is disabled by default.

## Affected products

- PowerDNS Authoritative Server 4.9.0 to 4.9.15, 5.0.0 to 5.0.5, 5.1.0 to 5.1.1

## Timeline

- 2026-06-25: disclosed
- 2026-06-25: advisory

## References

- [https://repo.powerdns.com/](https://repo.powerdns.com/)
- [https://docs.powerdns.com/authoritative/security-advisories/powerdns-advisory-powerdns-2026-07.html](https://docs.powerdns.com/authoritative/security-advisories/powerdns-advisory-powerdns-2026-07.html)

## Related threats

- [PowerDNS Authoritative Server denial of service in catalog zone transfer](https://junglewise.ai/threats/cve-2026-42396-powerdns-authoritative-server-denial-of-service-in-catalog-zone)
- [PowerDNS Authoritative Server denial of service in GSS-TSIG](https://junglewise.ai/threats/cve-2026-42002-powerdns-authoritative-server-denial-of-service-in-gss-tsig)
- [PowerDNS Authoritative Server insufficient validation of Autoprimary SOA queries](https://junglewise.ai/threats/cve-2026-42001-powerdns-authoritative-server-insufficient-validation-of)
- [PowerDNS Authoritative Server insufficient name validation in AXFR](https://junglewise.ai/threats/cve-2026-42000-powerdns-authoritative-server-insufficient-name-validation-in)
- [PowerDNS Authoritative Server incorrect view handling with TCP PROXY](https://junglewise.ai/threats/cve-2026-41999-powerdns-authoritative-server-incorrect-view-handling-with-tcp)