---
cve: "CVE-2026-49412"
severity: "HIGH"
cvss: 7.8
epss: "10%"
vendor: "FreeBSD"
kev: false
exploited: false
published: "2026-06-27 09:16:23"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T11:29:24+02:00"
---

# CVE-2026-49412

> 7.8 HIGH

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Referenzen

- <https://security.freebsd.org/advisories/FreeBSD-SA-26:29.ip6_multicast.asc>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-49412) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_