SB2026082003 - Red Hat Enterprise Linux 8 update for kernel-rt
Published: August 20, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 10 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2024-56602)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.5 [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]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error within the ieee802154_create() function in net/ieee802154/socket.c. A local user can escalate privileges on the system.
2) Use-after-free (CVE-ID: CVE-2026-46120)
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 ip6erspan_changelink() when changing link configuration after network namespace migration. A local user can trigger tunnel reinsertion into the wrong per-netns hash to cause a denial of service.
The issue is reachable from an unprivileged user namespace.
3) Use-after-free (CVE-ID: CVE-2026-52991)
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 pressure_write() in kernel/cgroup/cgroup.c when handling a write to a pressure cgroup file during concurrent cgroup file release. A local user can write crafted pressure data while racing cgroup file release to cause a denial of service.
The issue occurs because the of->priv pointer may be freed concurrently and later dereferenced.
4) Use-after-free (CVE-ID: CVE-2026-53189)
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 __split_huge_pmd_locked() when splitting a huge PMD mapping. A local user can trigger the affected memory-management path to cause a denial of service.
The issue occurs because file/shmem RSS accounting may access freed folio state after the last folio reference is dropped.
5) Double free (CVE-ID: CVE-2026-63888)
CWE-ID: CWE-415 - Double Free
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a double free in iscsit_handle_text_cmd() when handling a Text PDU with a bad DataDigest on connections using ErrorRecoveryLevel greater than 0. A remote user can send a specially crafted text request to cause a denial of service.
On hardened kernels the flaw can trigger a remote kernel BUG(), while on non-hardened kernels it can corrupt the slab freelist. A follow-up Text Request on the same ITT or session teardown can free the same pointer again.
6) Out-of-bounds read (CVE-ID: CVE-2026-63888)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in iscsit_handle_text_cmd() when processing Text PDUs with DataDigest enabled. A remote user can send a specially crafted text request to cause a denial of service.
The issue is triggered when DataDigest is negotiated for the connection.
7) Heap-based buffer overflow (CVE-ID: CVE-2026-63887)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow in iscsi_encode_text_output() when processing iSCSI login text parameters. A remote attacker can send a specially crafted login request with many minimal key-value pairs to cause a denial of service.
The issue can be triggered by expansion of unknown keys into larger "NotUnderstood" response records during login negotiation.
8) NULL pointer dereference (CVE-ID: CVE-2026-64048)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a null pointer dereference in smc_v2_determine_accepted_chid and smc_conn_create when processing a crafted SMC-Dv2 accept reply with CHID 0. A remote attacker can send a specially crafted reply to trigger a kernel fault and cause a denial of service.
Exploitation requires a malicious peer to reply to an SMC-Dv2-only proposal.
9) Improper input validation (CVE-ID: CVE-2026-64379)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to modify file mode bits.
The vulnerability exists due to improper input validation in parse_dacl() when processing a server-provided NFS mode SID. A remote attacker can provide crafted mode values to modify file mode bits.
The issue occurs when modefromsid is active.
10) Out-of-bounds read (CVE-ID: CVE-2026-68388)
CWE-ID: CWE-125 - Out-of-bounds read
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 an out-of-bounds read in smb3_simple_fallocate_range() when handling server-reported allocated ranges during fallocate operations. A local user can trigger fallocate on an SMB client mount backed by a server that returns overlapping or malformed allocated ranges to cause a denial of service.
A later write to a skipped hole may fail with ENOSPC.
Remediation
Install update from vendor's website.