CVE-2026-41285: In OpenBSD through 7.8, the slaacd and rad daemons have an infinite loop when they receive a crafted ICMPv6 Ne

Q: How do I fix CVE-2026-41285?

openbsd: upgrade to newer than 7.8. Exact commands for each OS are on this page.

Q: Is CVE-2026-41285 being exploited?

CVE-2026-41285 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-41285 affect?

CVE-2026-41285 affects openbsd. Severity is medium (CVSS 4.3). 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 preced

Q: How urgent is CVE-2026-41285?

Priority 18/100. No elevated risk signals yet.

Routine

MEDIUM 4.3UPGRADE

CVE-2026-41285 is a medium-severity flaw (CVSS 4.3) affecting openbsd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 89%)
CISA exploited list	No
Weakness	CWE-1284, CWE-835
Published	2026-04-21
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: openbsd

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-21 00:16 UTCPublished CVE record published
2026-06-17 10:46 UTCUpdated Record last modified

openbsd openbsd UPGRADE

Affected: <= 7.8

Fixed in: newer than 7.8

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41285?

openbsd: upgrade to newer than 7.8. Exact commands for each OS are on this page.

Is CVE-2026-41285 being exploited?

CVE-2026-41285 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41285 affect?

CVE-2026-41285 affects openbsd. Severity is medium (CVSS 4.3). 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 preced

How urgent is CVE-2026-41285?

Priority 18/100. No elevated risk signals yet.

Related CVEs

CVE-2026-56099 MEDIUM 5.3 UPGRADE OpenBSD before commit 6a23123 (2026-06-18) contains an out-of-bounds read vulnerability in the mpls_do_error f
CVE-2026-55706 MEDIUM 5.8 UPGRADE sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows authentication bypass via certain zer
CVE-2026-57589 HIGH 7.4 UPGRADE sys/kern/sysv_sem.c in OpenBSD through 7.9 has a use-after-free allowing local privilege escalation to root

References

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