CVE-2025-21759

HighCVSS 7.8/10Last modified Oct 3, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

ipv6: mcast: extend RCU protection in igmp6_send()

igmp6_send() can be called without RTNL or RCU being held.

Extend RCU protection so that we can safely fetch the net pointer and avoid a potential UAF.

Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.

Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection.

Metrics

CVSS 3.1 7.8/10CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-416

Affected software

No affected versions have been published.

Timeline

Published
Feb 27, 2025
Last modified
Oct 3, 2026
NVD status
Modified

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CVE-2025-21759: High severity, CVSS 7.8 | Vulnix