SB2026061693 - Red Hat Enterprise Linux 8 update for kernel-rt
Published: June 16, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-31669)
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 __inet_lookup_established when performing concurrent ehash lookups on MPTCP IPv6 subflow child sockets under rcu_read_lock. A local user can trigger socket allocation and freeing patterns to cause a denial of service.
The issue affects MPTCP IPv6 subflow child sockets because they may be allocated from a cache without SLAB_TYPESAFE_BY_RCU, allowing freed memory to be reused during lockless lookups.
2) Double free (CVE-ID: CVE-2026-31787)
CWE-ID: CWE-415 - Double Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local privileged user to circumvent kernel lockdown restrictions.
The vulnerability exists due to double free in the Linux kernel privcmd driver when handling privcmd operations. A local privileged user can trigger a double free of kernel memory to circumvent kernel lockdown restrictions.
Only Linux PVH or HVM domains booted in secure mode are affected; PV domains and non-Linux domains are not vulnerable.
3) Out-of-bounds read (CVE-ID: CVE-2026-31786)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to disclose sensitive information, cause a denial of service, or escalate privileges.
The vulnerability exists due to an out-of-bounds read in the Xen-related sysfs buildid handler when reading the /sys/hypervisor/properties/buildid sysfs file. A local user can read the crafted sysfs output to disclose sensitive information, cause a denial of service, or escalate privileges.
In rare cases, the issue may also result in writing past the 4 kB sysfs buffer if no zero byte is found in adjacent data.
4) Out-of-bounds read (CVE-ID: CVE-2026-43110)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in brcmf_fweh_handle_if_event() when handling firmware-provided IF events. A remote attacker can supply a crafted bsscfg index to cause a denial of service.
5) Memory corruption (CVE-ID: CVE-2026-43329)
CWE-ID: CWE-119 - Memory corruption
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper restriction of operations within the bounds of a memory buffer in flowtable hardware offload action handling when processing IPv6 flowtable offload configurations with multiple actions. A remote attacker can trigger a flow configuration that exceeds the supported number of actions to cause a denial of service.
The issue can be reached in IPv6 setups involving combinations of ethernet mangling, NAT, double VLAN for QinQ, redirect, and tunnel-related actions.
6) Use-after-free (CVE-ID: CVE-2026-46056)
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 SSP passkey handlers when handling Bluetooth SSP passkey and keypress notification events. A local user can trigger concurrent connection teardown during event processing to cause a denial of service.
7) Race condition (CVE-ID: CVE-2026-46152)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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 cause incorrect packet processing.
The vulnerability exists due to a race condition in ieee80211_invoke_fast_rx() when processing packets in parallel RX paths. A local user can trigger concurrent packet processing to cause incorrect packet processing.
This issue arises because concurrent callers share a single rx_result instance, which can be overwritten between ieee80211_rx_mesh_data() and the subsequent switch on the result.
8) Use-after-free (CVE-ID: CVE-2026-46125)
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 debugfs when handling failed connection preparation for mlo connections. A local user can trigger connection preparation failure and access the affected debugfs state to cause a denial of service.
The issue occurs when debugfs is enabled and an interface is reset from mld to non-mld, which recreates its debugfs entries.
Remediation
Install update from vendor's website.