CVE-2025-21759

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.

CVSS 3.1

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

EPSS

7.8% chance of exploitation in the next 30 days; higher than 94% of CVEs (scores of 2026-10-25)

CWE

CWE-416

Published

2025-02-27

Modified

2026-10-03

Record from

the NVD, synced 2026-10-19

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/087c1faa594fa07a66933d750c0b2610aa1a2946
• https://git.kernel.org/stable/c/0bf8e2f3768629d437a32cb824149e6e98254381
• https://git.kernel.org/stable/c/638e8fe3563a82f298fe537a28d5342a97278cf1
• https://git.kernel.org/stable/c/6901bbb169e3add6c037218d996790cef6b3d650
• https://git.kernel.org/stable/c/7e0a818ecc4d62e7fb668ea02de0bfe8ba0b7dff

Check your stackJSON