Use-after-free in Linux kernel - CVE-2026-64423
Published: July 27, 2026
Vulnerability identifier: #VU139518
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64423
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in the IGMP multicast group handling in net/ipv4/igmp.c when destroying a device while concurrent RCU readers traverse the multicast hash table. A local user can trigger multicast group membership operations and concurrent network processing to cause a denial of service.
The issue occurs because multicast group entries can remain reachable through the device multicast hash table during RCU reclamation.
Affected software
Linux kernel
How to mitigate CVE-2026-64423
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/2ca18df1c2611f70eb3eb487e02ae85eb703b284
- https://git.kernel.org/stable/c/412ba7def06ffe974ba9a1d862b022362c54ffa5
- https://git.kernel.org/stable/c/5f42729d74bd6c61306d864423290d92962de4e1
- https://git.kernel.org/stable/c/76d030ac95e17f91d69a595f17ebc5979700cf9a
- https://git.kernel.org/stable/c/7993211bde166471dffac074dc965489f86531f8
- https://git.kernel.org/stable/c/8820b530cb2388503d7418228d03ba074bf7a03e
- https://git.kernel.org/stable/c/c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9
- https://git.kernel.org/stable/c/f91883031e5a62877a29ce139442973cbea769f1