SB20260731178 - Red Hat Enterprise Linux 8 update for kernel-rt
Published: July 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Improper access control (CVE-ID: CVE-2026-31692)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to create interfaces in arbitrary network namespaces.
The vulnerability exists due to improper access control in rtnl_newlink() when creating paired devices with a peer network namespace. A local user can create veth, vxcan, or netkit interfaces to create interfaces in arbitrary network namespaces.
Exploitation requires a user namespace.
2) Use-after-free (CVE-ID: CVE-2026-43116)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in netfilter ctnetlink expectation handling when processing expectation add, delete, get, or event operations. A local user can trigger access to an invalid master conntrack object to cause a denial of service.
3) Improper access control (CVE-ID: CVE-2026-46150)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to bypass permission checks.
The vulnerability exists due to improper access control in fsnotify_get_mark_safe() when processing fanotify permission events. A local user can trigger permission events in the presence of an unrelated detached mark to bypass permission checks.
4) Use-after-free (CVE-ID: CVE-2026-64530)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in tcf_qevent_handle in net/sched/cls_api.c when handling TC_ACT_CONSUMED during qevent processing of fragmented traffic. A local user can send specially crafted fragmented network traffic to trigger use of an skb after ownership has been transferred and cause a denial of service.
Exploitation requires RED qdisc qevents together with ct defragmentation and traffic that produces out-of-order fragments.
Remediation
Install update from vendor's website.