CVE-2026-41285 Denial of service in OpenBSD
A remote attacker can cause a denial of service in OpenBSD's slaacd and rad daemons by sending a crafted ICMPv6 packet with a zero-length option.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-41285?
CVE-2026-41285 is a medium-severity denial of service vulnerability in Openbsd Openbsd, published on 20 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In OpenBSD through 7.8, the slaacd and rad daemons have an infinite loop when they receive a crafted ICMPv6 Neighbor Discovery (ND) option (over a local network) with length zero, because of an "nd_opt_len * 8 - 2" expression with no preceding check for whether nd_opt_len is zero.
Which versions are affected by CVE-2026-41285?
It affects 1 product.
Products include Openbsd Openbsd.
How do I fix CVE-2026-41285?
No fix has been published for CVE-2026-41285 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-41285 being exploited?
There is no known exploitation of CVE-2026-41285 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Openbsd Openbsd
Sources
Also known as GHSA-h2gc-758g-276m.