Vulnerability in OpenBSD
CVE-2026-41285
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.003 (15.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000
Affected products
- OpenBSD — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.rfc-editor.org/rfc/rfc4861 (Not Applicable)
- github.com/openbsd/src/commit/086c5738bcd3c203bcc08d024fcf983cb409115f (Patch)
- www.openbsd.org/errata78.html (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-41285?
- CVE-2026-41285 is a medium-severity vulnerability in OpenBSD, classified under Improper Validation of Specified Quantity in Input. CVSS score: 4.3/10. Published 2026-04-21.
- How severe is CVE-2026-41285?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2026-41285 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.