SB2026101934 - Red Hat Enterprise Linux 8 update for kernel
Published: October 19, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-43450)
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 out-of-bounds read in nfnl_cthelper_dump_table() when handling netlink dump requests after a previously saved helper entry is deleted between dump rounds. A local user can trigger the affected dump logic to cause a denial of service.
The issue is triggered when the saved "last" helper is deleted between dump rounds, causing a restart path to bypass the loop bounds check.
2) Out-of-bounds read (CVE-ID: CVE-2026-46149)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in tg_pt_gp_members_show() when formatting and copying LUN paths to a sysfs reader. A local user can read the affected sysfs entry with a long fabric WWN value to disclose sensitive information.
When CONFIG_FORTIFY_SOURCE is enabled, exploitation triggers fortify_panic() instead of leaking adjacent stack contents.
3) Use-after-free (CVE-ID: CVE-2026-53062)
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 use-after-free in the dm-cache smq policy invalidate_mapping operation when handling concurrent writes in passthrough mode. A local user can trigger concurrent cache block invalidations to cause a denial of service.
The issue occurs when the cache is operating in passthrough mode and multiple workers invalidate cache blocks simultaneously.
4) Use-after-free (CVE-ID: CVE-2026-63802)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/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 use-after-free in __blkcg_rstat_flush() when releasing multiple blkgs in the same blkcg concurrently. A local user can trigger concurrent blkg release operations to cause a denial of service.
The race occurs when one blkg removes another blkg's iostat entries via llist_del_all() while the other blkg is still being processed.
5) Use of Out-of-range Pointer Offset (CVE-ID: CVE-2026-63924)
CWE-ID: CWE-823 - Use of Out-of-range Pointer Offset
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 improper pointer handling in the IPv6 extension header parser in net/ipv6/exthdrs.c when processing IPv6 jumbo hop-by-hop options. A remote attacker can send a specially crafted IPv6 packet to cause a denial of service.
6) Use-after-free (CVE-ID: CVE-2026-63922)
CWE-ID: CWE-416 - Use After Free
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 use-after-free risk from stale pointer reuse in ip6_parse_tlv() in net/ipv6/exthdrs.c when parsing IPv6 TLVs containing the HAO option. A remote attacker can send a specially crafted IPv6 packet to cause a denial of service.
The issue occurs when handling a cloned skb where header expansion moves the skb head and invalidates the cached network header pointer.
7) Out-of-bounds read (CVE-ID: CVE-2026-63920)
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:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in ip6_datagram_recv_specific_ctl() when processing IPv6 extension headers for recvmsg control messages after the hdrlen field is modified. A local user can use an nftables payload-write expression to corrupt the extension header length and trigger copying beyond the available header data to disclose sensitive information.
Exploitation is reachable from an unprivileged user namespace.
Remediation
Install update from vendor's website.