CVE-2026-41292

Long list of incoming EDNS options degrades performance

HIGH
7.5
CVSS Score
Published: May 20, 2026 at 09:19 AM UTC
Updated: August 26, 2026 at 01:18 PM UTC
3 products affected across 2 vendorsUnboundEnterprise LinuxOpenStack Platform

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Severity
HIGH7.5
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

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).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.25.1
Affected range stops below 1.25.1, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 0:1.16.2-5.12.el8_10 (unaffected)
Vendor states this is fixed in 0:1.24.2-3.el9_8.2 (unaffected)
Vendor states this is fixed in 0:1.24.2-7.el10_2.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (9)

Vendor AdvisoryMitigation
Source: cverecord
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-41292.txt
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/security/cve/CVE-2026-41292
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://bugzilla.redhat.com/show_bug.cgi?id=2480125
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:24013
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:36320
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:36777
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:37282

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHredhat-SADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-407CWE-770CWE-1050

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