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).
Project Subscriptions
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Advisories
No advisories yet.
Fixes
Solution
This issue is fixed starting with version 1.25.1
Workaround
No workaround given by the vendor.
References
History
Wed, 20 May 2026 10:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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). | |
| Title | Long list of incoming EDNS options degrades performance | |
| Weaknesses | CWE-407 CWE-770 |
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| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: NLnet Labs
Published:
Updated: 2026-05-20T09:19:13.022Z
Reserved: 2026-05-07T10:13:43.992Z
Link: CVE-2026-41292
No data.
Status : Received
Published: 2026-05-20T10:16:27.327
Modified: 2026-05-20T10:16:27.327
Link: CVE-2026-41292
No data.
OpenCVE Enrichment
Updated: 2026-05-20T11:30:26Z