CVE-2026-41292
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.
Does this matter?
Lower severity and a low EPSS score (0.72%). Track it; it rarely justifies an emergency change on its own.
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).
- CVSS 4.0
- 6.6 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.72% probability · 52th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-407, CWE-770, CWE-1050
- Affected
- nlnetlabs/unbound
- Source
- sep@nlnetlabs.nl
References
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-41292.txtMitigation, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:24013
- https://access.redhat.com/errata/RHSA-2026:36320
- https://access.redhat.com/errata/RHSA-2026:36777
- https://access.redhat.com/errata/RHSA-2026:37282
- https://access.redhat.com/errata/RHSA-2026:54769
- https://access.redhat.com/security/cve/CVE-2026-41292
- https://bugzilla.redhat.com/show_bug.cgi?id=2480125
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41292.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.