CVE-2026-41292: NLnet Labs Unbound · Inefficient Algorithmic Complexity
Affects NLnet Labs UnboundSource CVE Database V5
Not known to be exploited · CVSS 6.6 Medium : upgrade to 1.25.1 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.25.1
CVSS: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/U:RedExploitation evidence
Disclosed: evidence found.
CVE published 20 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade NLnet Labs Unbound to 1.25.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| NLnet LabsUnbound | Affected
| Fixed in
|
AI-suggested
A fix is available in Unbound version 1.25.1, which limits the number of acceptable incoming EDNS options to 100. Users should upgrade to version 1.25.1 or later to remediate this vulnerability. No other specific mitigations are indicated by the vendor advisory.
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).
References
- nlnetlabs.nl/downloads/unbound/CVE-2026-41292.txt (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-41292 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2480125 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41292.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36320 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37282 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36777 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:24013 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54769 (opens in a new tab)