Degradation of Service Vulnerability in NLnetLabs Unbound
CVE-2026-80225

5.3MEDIUM

Key Information:

Vendor

Nlnet Labs

Status
Unbound
Vendor
CVE Published:
16 September 2026

What is CVE-2026-80225?

In NLnetLabs Unbound, a service degradation vulnerability is introduced due to the absence of limits on consecutive reads during the TCP/DoT reading procedure. This flaw allows an attacker to monopolize a worker's event loop by streaming a sequence of distinct uncached names over a TCP/DoT connection, potentially causing significant disruptions. Affected users are advised to take immediate action to mitigate risks associated with this vulnerability.

Affected Version(s)

Unbound 0 < 1.26.1

References

https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-80225...
vendor-advisory

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Qifan Zhang (Palo Alto Networks)
.