CVE-2026-6949
MediumSummary
A TSIG packet with name compression can crash DNS. Incorrect size calculations when a TSIG record contains compressed names lead to a large out-of-bounds write, causing a server crash.
Risk Assessment
The risk is a DNS server crash, which could disrupt name resolution and impact network availability.
Recommendation
Apply patches from the DNS software vendor immediately and restrict the use of name compression in TSIG records.
Other vulnerabilities in DNS
See all- CVE-2023-50387High
The KeyTrap vulnerability in the DNSSEC protocol allows a remote attacker to cause a Denial of Service (DoS) by sending DNSSEC responses containing many DNSKEY and RRSIG records. This leads to excessive CPU consumption on the DNS server, potentially causing overload.
- CVE-2026-52684Low
A DNS issue occurs when the authoritative server responds very slowly and records expire in the meantime. In this case, TTL capping is not enforced due to lack of data. This does not happen during normal resolution.
- CVE-1999-1379Medium
The vulnerability in DNS allows remote attackers to use DNS name servers as traffic amplifiers. An attacker can send a UDP DNS query with a spoofed source address, resulting in more traffic to the victim than was sent by the attacker.
Original NVD description (English source)
TSIG packet with name compression can crash DNS. Incorrect size calculations when a TSIG record contains compressed names can lead to a large out-of-bounds write causing the server to crash.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS