SB20260921196 - SUSE update for the Linux Kernel (Live Patch 44 for SUSE Linux Enterprise 15 SP5)
Published: September 21, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-64423)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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]
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.
2) Race condition (CVE-ID: CVE-2026-68138)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition leading to use-after-free and double-free in qdisc_get_rtab() and qdisc_put_rtab() when processing concurrent RTM_NEWTFILTER requests that add flower filters with a police action carrying the same rate. A local user can send concurrent netlink filter configuration requests to cause a denial of service.
The corrupted qdisc_rate_table object is shared system-wide because the affected rate-table list is process-global rather than per-network-namespace.
Remediation
Install update from vendor's website.