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

> An attacker controlling a domain can cause excessive network traffic and resource exhaustion in Technitium DNS Server by triggering aggressive DNSSEC record fetches.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 May 2026
- **Updated:** 19 May 2026
- **Also known as:** GHSA-vpfg-gc96-vg45

## What is CVE-2026-45557?

CVE-2026-45557 is a medium-severity denial of service vulnerability in Technitium DNS Server, published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-406 (Insufficient Control of Network Message Volume (Network Amplification)), CWE-405 (Asymmetric Resource Consumption (Amplification))

## Which versions are affected by CVE-2026-45557?


## How do I fix CVE-2026-45557?

No fix has been published for CVE-2026-45557 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-45557 being exploited?

There is no known exploitation of CVE-2026-45557 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45557 and fix it if it is affected.

What it is: CVE-2026-45557 is a medium-severity denial of service vulnerability in Technitium DNS Server, published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45557 in the wild and no public exploit code.

Affected product: Technitium DNS Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45557/ (Markdown: https://insights.sbomify.com/CVE-2026-45557/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45557
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45557
- OSV: https://osv.dev/vulnerability/CVE-2026-45557

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45557/
Summaries are generated and may contain mistakes; the official description above is the record.