CVE-2026-33258
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk48th percentile - higher than 48% of all known CVEs
Summary
In a DNS system, an attacker can publish and query a crafted zone to cause allocation of large entries in the negative and aggressive NSEC(3) caches.
Risk Assessment
This may lead to memory exhaustion and denial of service (DoS) on the DNS server.
Recommendation
Update DNS software to a patched version and monitor cache memory usage.
Other vulnerabilities in DNS
See all- CVE-2026-6949Medium
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.
- 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-2026-33261Medium
A zone transition from NSEC to NSEC3 might trigger an internal inconsistency and cause a denial of service.
- CVE-2025-59029Medium
An attacker can trigger an assertion failure by requesting crafted DNS records, waiting for them to be inserted into the records cache, then sending a query with qtype set to ANY.
- CVE-2025-2962High
A denial-of-service issue in the DNS implementation could cause an infinite loop. This may lead to a hang or unavailability of the service.
- CVE-2025-1674High
A lack of input validation allows for out-of-bounds reads caused by malicious or malformed packets. This may lead to data disclosure or a crash.
- CVE-2025-1673High
A malicious or malformed DNS packet without a payload can cause an out-of-bounds read, resulting in a crash (denial of service) or an incorrect computation. The vulnerability affects DNS packet processing.
- 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)
By publishing and querying a crafted zone an attacker can cause allocation of large entries in the negative and aggressive NSEC(3) caches.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

