Description
The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock. During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.

An unprivileged local user can exploit this use-after-free to escalate privileges.
Published: 2026-06-27
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Sat, 27 Jun 2026 09:15:00 +0000

Type Values Removed Values Added
Description The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock. During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory. An unprivileged local user can exploit this use-after-free to escalate privileges.
Title Use-after-free bug in the IPV6_MSFILTER socket option handler
Weaknesses CWE-416
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-06-27T09:02:55.482Z

Reserved: 2026-05-29T20:24:28.615Z

Link: CVE-2026-49412

cve-icon Vulnrichment

No data.

cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

Updated: 2026-06-27T10:30:14Z

Weaknesses