SB2026081850 - Red Hat Enterprise Linux 9 update for multiple packages
Published: August 18, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-43038)
CWE-ID: CWE-125 - Out-of-bounds read
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 an out-of-bounds read in ip6_err_gen_icmpv6_unreach() when processing a forged ICMPv4 error containing a CIPSO IP option and an attacker-controlled inner IPv6 packet. A remote attacker can send a specially crafted ICMP error packet to cause a denial of service.
The issue arises because IPv4 control buffer data is reused as IPv6 control buffer data in a cloned skb, which can lead to a forged home address option offset being used during IPv6 TLV parsing.
2) Out-of-bounds write (CVE-ID: CVE-2026-43125)
CWE-ID: CWE-787 - Out-of-bounds write
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 an out-of-bounds write in dlm_search_rsb_tree() when processing network messages with an excessive resource name length. A remote attacker can send a specially crafted network message to cause a denial of service.
The length value originates from the len parameter in dlm_dump_rsb_name().
3) Memory corruption (CVE-ID: CVE-2026-43329)
CWE-ID: CWE-119 - Memory corruption
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 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.
4) Use-after-free (CVE-ID: CVE-2026-64530)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6 [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]
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.