← Vulnerability feed

Vulnerability record · CVE-2025-21759 · published 27 February 2025

CVE-2025-21759: Linux kernel use after free vulnerability

Linux · Linux Kernel

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.

7.8 CVSS 3.1 High EPSS 7.8% · top 5.6% CWE-416 · Use after free
7.8CVSS 3.1 base score
7.8%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://git.kernel.org/stable/c/087c1faa594fa07a66933d750c0b2610aa1a2946 Patch
https://git.kernel.org/stable/c/0bf8e2f3768629d437a32cb824149e6e98254381 Patch
https://git.kernel.org/stable/c/81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a Patch
https://git.kernel.org/stable/c/8e92d6a413feaf968a33f0b439ecf27404407458 Patch

Track CVE-2025-21759 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2025-39682Linux kernel TLS zero-length record handling flaw on rx_listThe Linux kernel TLS receive path mishandles zero-length records that arrive from the rx_list, breaking the assumption that a record type change cann…KEVEPSS 2.9%analysed8.8CVE-2026-53266Linux kernel ebtables SNAT out-of-bounds write in ARP rewriteThe ebtables SNAT target rewrites the ARP sender hardware address via skb_store_bits() without first making that range writable. When the ARP SHA byt…KEVEPSS 0.65%analysed8.8CVE-2023-3079Google Chrome V8 type confusion enables heap corruptionCVE-2023-3079 is a type confusion flaw in the V8 JavaScript engine in Google Chrome before 114.0.5735.110. A crafted HTML page can trigger the confus…KEVEPSS 32%analysed8.8CVE-2013-6282Linux kernel ARM get_user/put_user missing address validationThe get_user and put_user API functions in the Linux kernel before 3.5.5 on v6k and v7 ARM platforms fail to validate certain addresses, allowing cra…KEVEPSS 40%analysed8.4CVE-2022-0185Linux Kernel Filesystem Context Heap Buffer OverflowThe legacy_parse_param function in the Linux kernel's Filesystem Context functionality fails to properly verify supplied parameter lengths, causing a…KEVEPSS 25%analysed8.4CVE-2013-2094Linux Kernel perf_swevent_init Integer Type Flaw Enables Local Privilege EscalationThe perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, allowing a local user to…KEVEPSS 48%analysed7.8CVE-2026-53362Linux kernel IPv6 UDP paged allocation out-of-bounds write__ip6_append_data() in the Linux kernel mis-accounts fraggap on the paged-allocation path, leaving the linear skb area undersized while pagedlen is o…KEVEPSS 0.71%analysed7.8CVE-2026-31431Linux kernel algif_aead in-place crypto operation flawThe Linux kernel's algif_aead AF_ALG AEAD interface operated in-place on buffers that come from different mappings, a flaw the fix resolves by revert…KEVEPSS 3.4%analysed

Source: NIST National Vulnerability Database (record CVE-2025-21759), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.