CVE-2026-41285Public exploit

IPv6 service interruption via zero-length ND option

Published Apr 20, 2026 · Updated Apr 20, 2026

Denial of service in OpenBSD slaacd and rad 7.8 and earlier allows remote attackers to interrupt IPv6 services over a local network. The ND option parsers subtract two from nd_opt_len * 8 without rejecting zero, move the parsing position backward, and loop indefinitely. A device on the same Layer 2 segment can hang either daemon with one malformed ICMPv6 packet, stopping SLAAC or router-advertisement handling until the daemon restarts.

CVSS severity4.3
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in OpenBSD slaacd and rad 7.8 and earlier allows remote attackers to interrupt IPv6 services over a local network. The ND option parsers subtract two from nd_opt_len * 8 without rejecting zero, move the parsing position backward, and loop indefinitely. A device on the same Layer 2 segment can hang either daemon with one malformed ICMPv6 packet, stopping SLAAC or router-advertisement handling until the daemon restarts.

The record

CVE
CVE-2026-41285
Published
Apr 20, 2026
Updated
Apr 20, 2026
Vendor
OpenBSD Project
Product
OpenBSD
Classifications
CWE-835, CWE-1284, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=7.8

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

OpenBSD Project · OpenBSDversion=0 <=7.8

Published CVSS scores

4.3MITRECVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
CWE-1284Improper Validation of Specified Quantity in Input
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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