DNS amplification via aggressive DNSSEC record fetching
Published May 19, 2026 · Updated May 19, 2026
DNS amplification in Technitium DNS Server before 15.0 allows remote attackers controlling a domain to generate excessive network traffic. During DNSSEC validation, the recursive resolver repeatedly fetches missing RRSIG records or DNSKEY records that do not match a response instead of bounding follow-up requests. The server must recursively resolve an attacker-controlled DNSSEC domain; the outbound request burst consumes network capacity and degrades DNS service.
Summary
What happened
DNS amplification in Technitium DNS Server before 15.0 allows remote attackers controlling a domain to generate excessive network traffic. During DNSSEC validation, the recursive resolver repeatedly fetches missing RRSIG records or DNSKEY records that do not match a response instead of bounding follow-up requests. The server must recursively resolve an attacker-controlled DNSSEC domain; the outbound request burst consumes network capacity and degrades DNS service.
The record
- CVE
- CVE-2026-45557
- Published
- May 19, 2026
- Updated
- May 19, 2026
- Vendor
- Technitium
- Product
- Technitium DNS Server
- Classifications
- CWE-405, CWE-406, CWE-770, T1499.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 19, 2026CVE publishedPublication date reported by the CVE source.
- May 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <15.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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