Vulnerability in Linux

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.

EPSS: 0.133 (96.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21758?
CVE-2025-21758 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2025-02-27.
How severe is CVE-2025-21758?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21758 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.