CVE-2026-41292 Long list of incoming EDNS options degrades performance

What is CVE-2026-41292?

CVE-2026-41292 is a medium-severity vulnerability in Nlnetlabs Unbound, published on 20 May 2026.

Official 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).

Weakness: CWE-1050, CWE-770, CWE-407

Which versions are affected by CVE-2026-41292?

It affects 1 product.

Products include Nlnetlabs Unbound.

How do I fix CVE-2026-41292?

Upgrade to a fixed version.

Is CVE-2026-41292 being exploited?

There is no known exploitation of CVE-2026-41292 in the wild and no public exploit code.

Other vulnerabilities in Nlnetlabs Unbound

• CVE-2026-81642 Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY Critical 9.1
• CVE-2026-33278 Possible arbitrary code execution during DNSSEC validation Critical 9.1
• CVE-2026-42944 Heap overflow with multiple NSID, COOKIE, PADDING EDNS options High 8.7
• CVE-2026-42959 Crash during DNSSEC validation of malicious content High 8.7
• CVE-2026-82717 CNAME synthesis could lead to heap corruption High 8.4

All Nlnetlabs Unbound vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2026-41292, AZL-87030, DEBIAN-CVE-2026-41292, ECHO-a55d-d403-6e56, GHSA-2wvj-gvc7-gfhx, ROOT-OS-DEBIAN-11-CVE-2026-41292 and 2 more.