CVE-2026-41292
HIGHUnbound <= 1.25.0 - Denial of Service via EDNS Option Parsing
Title source: llmDescription
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).
References (1)
Core 1
Core References
Vendor Advisory vendor-advisory
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-41292.txt
Scores
CVSS v3
7.5
EPSS
0.0043
EPSS Percentile
34.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-407
CWE-770
Status
published
Products (2)
NLnet Labs/Unbound
< 1.25.1
nlnetlabs/unbound
< 1.25.1
Published
May 20, 2026
Tracked Since
May 20, 2026