CVE-2025-21758

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: add RCU protection to mld_newpack() mld_newpack() can be called without RTNL or RCU being held. 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

5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

17% chance of exploitation in the next 30 days; higher than 97% of CVEs (scores of 2026-10-25)

Published

2025-02-27

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/1b91c597b0214b1b462eb627ec02658c944623f2
• https://git.kernel.org/stable/c/25195f9d5ffcc8079ad743a50c0409dbdc48d98a
• https://git.kernel.org/stable/c/29fa42197f26a97cde29fa8c40beddf44ea5c8f3
• https://git.kernel.org/stable/c/a527750d877fd334de87eef81f1cb5f0f0ca3373
• https://git.kernel.org/stable/c/d60d493b0e65647e0335e6a7c4547abcea7df8e9

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