VulnerabilityPublished 20 Apr 2026Updated 21 Apr 2026

CVE-2026-41285: OpenBSD versions through 7.8 contain a

Source CVE Database V5

Not known to be exploited.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated Medium by the CNA (mitre) · No CVSS score from NVD or the CNA

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
OpenBSDOpenBSD	Affected <=7.8	Fixed in–

AI-suggested

Until an official fix is available, network administrators should consider limiting ICMPv6 Neighbor Discovery traffic from untrusted sources on local networks to reduce exposure. Monitor vendor channels for updates and apply patches once released.

Description

OpenBSD versions through 7.8 contain a vulnerability in the slaacd and rad daemons where receiving a crafted ICMPv6 Neighbor Discovery option with zero length causes an infinite loop. This occurs due to a missing check for zero length before evaluating an expression involving the option length. The issue is triggered over a local network and can cause daemon malfunction.

Impact

The vulnerability causes the slaacd and rad daemons to enter an infinite loop upon receiving a crafted ICMPv6 Neighbor Discovery option with zero length. This can lead to denial of service by disrupting these network services on affected OpenBSD systems. There is no indication of remote code execution or privilege escalation. Exploitation requires local network access to send the crafted ICMPv6 packets.

Summary

CVE-2026-41285 affects OpenBSD through version 7.8 in the slaacd and rad daemons. When these daemons receive an ICMPv6 Neighbor Discovery option with a length of zero, they enter an infinite loop because the code evaluates the expression "nd_opt_len * 8 - 2" without first verifying that nd_opt_len is non-zero. This lack of validation leads to improper handling of malformed ND options, resulting in a denial of service condition on the affected daemons.

References

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