# CVE-2026-45557: Technitium DNS Server resource consumption via DNSSEC record fetching

Source: https://junglewise.ai/threats/cve-2026-45557-technitium-dns-server-resource-consumption-via-dnssec-record  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-19. Updated: 2026-05-19  
License: CC BY 4.0 with a link back

CVE-2026-45557 · Severity: medium · CVSS 5.8 · Published 2026-05-19

Technitium DNS Server is a tool used to manage network traffic and domain name resolution. A vulnerability in how it handles security records allows an attacker to force the server into a loop of aggressive network requests. This can lead to excessive network traffic, potentially slowing down the server or causing a denial-of-service condition for legitimate users.

## Quick answers

**Is CVE-2026-45557 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45557 being exploited in the wild.

**How severe is CVE-2026-45557?** Medium severity, with a CVSS score of 5.8, published 19 May 2026.

**Which products and versions are affected?** Technitium DNS Server Before 15.0.

**Is there a fix for CVE-2026-45557?** A patch was published on 2026-05-19: Fixed in version 15.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45557 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-45557?** Check whether anything you run is named in the advisory. 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

Technitium DNS Server is vulnerable to asymmetric resource consumption (amplification) due to insufficient control of network message volume. The server's DNSSEC validation logic aggressively attempts to fetch missing RRSIG records or resolve mismatched DNSKEY records when encountering specific domain configurations. An unauthenticated remote attacker in control of a malicious domain can exploit this behavior to force the DNS server to generate excessive outbound network traffic. This can lead to resource exhaustion or a denial-of-service (DoS) state. The issue is addressed in version 15.0.

## Affected products

- Technitium DNS Server Before 15.0

## Timeline

- 2026-05-19: advisory: CVE-2026-45557 published by NVD/CISA
- 2026-05-19: patched: Fixed in version 15.0

## References

- [https://github.com/TechnitiumSoftware/DnsServer/blo/master/CHANGELOG.md](https://github.com/TechnitiumSoftware/DnsServer/blo/master/CHANGELOG.md)
- [https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2025/va-26-138-02.json](https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2025/va-26-138-02.json)
- [https://www.cve.org/CVERecord?id=CVE-2026-45557](https://www.cve.org/CVERecord?id=CVE-2026-45557)