SB2026071792 - Red Hat Enterprise Linux 7 Extended Lifecycle Support update for kernel-rt



SB2026071792 - Red Hat Enterprise Linux 7 Extended Lifecycle Support update for kernel-rt

Published: July 17, 2026

Security Bulletin ID SB2026071792
CSH Severity
High
Patch available
YES
Number of vulnerabilities 16
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 6% Medium 38% Low 56%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 16 vulnerabilities.


1) Out-of-bounds read (CVE-ID: CVE-2026-23243)

CWE-ID: CWE-125 - Out-of-bounds read

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 boundary error in the RDMA/umad component when processing user-controlled MAD headers. A local user can send a specially crafted request with mismatched MAD header size and RMPP header length to cause a denial of service.

Exploitation requires access to the RDMA UMAD interface. The vulnerability can trigger an out-of-bounds write in kernel memory, leading to system instability or crash.


2) Out-of-bounds read (CVE-ID: CVE-2026-23455)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in DecodeQ931() in the nf_conntrack_h323 netfilter component when parsing a crafted Q.931 packet with a zero UserUserIE length field. A remote attacker can send a specially crafted packet to disclose sensitive information.

The issue occurs because a 16-bit length value is decremented by 1 to skip the protocol discriminator byte, and an encoded length of 0 wraps to -1 and is then passed to DecodeH323_UserInformation() as a large value.


3) Use-after-free (CVE-ID: CVE-2026-31532)

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 raw_rcv() when processing CAN frames after a raw CAN socket is released. A local user can trigger concurrent socket release and packet reception to cause a denial of service.

The issue involves the percpu uniq storage referenced through RCU-delayed receiver deletion.


4) Heap-based buffer overflow (CVE-ID: CVE-2026-31607)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

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 or execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in usbip_pack_ret_submit() when processing a RET_SUBMIT response from a USB/IP server. A remote attacker can send a specially crafted response with an oversized number_of_packets value to cause a denial of service or execute arbitrary code.

The issue occurs because the response value is later used as the loop bound for accesses to urb->iso_frame_desc[], whose allocation size was determined by the original submission.


5) Improper input validation (CVE-ID: CVE-2026-31685)

CWE-ID: CWE-20 - Improper input validation

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 input validation in ip6t_eui64 when processing packets with an invalid MAC header. A remote attacker can send a specially crafted packet to cause a denial of service.


6) Stack-based buffer overflow (CVE-ID: CVE-2026-43037)

CWE-ID: CWE-121 - Stack-based buffer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a stack-based buffer overflow in ip4ip6_err() and __ip_options_echo() when processing a crafted packet that triggers ICMP error handling on a cloned skb. A remote attacker can send a specially crafted packet to execute arbitrary code.

The issue is caused by reusing skb cb[] data written by the IPv6 receive path as IPv4 metadata, allowing attacker-controlled packet data to influence the copied option length.


7) 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.


8) Use-after-free (CVE-ID: CVE-2026-43163)

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 race in write_page() when resizing an array while bitmap daemon work is iterating over bitmap->storage.filemap. A local user can trigger concurrent bitmap update and resize operations to cause a denial of service.

The issue occurs because the md thread can continue running during quiesce(), allowing concurrent access to freed pages.


9) Out-of-bounds read (CVE-ID: CVE-2026-43190)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in the xt_tcpmss TCP option parser when parsing a TCP option field whose last byte is not EOL or NOP. A local user can supply a specially crafted packet to disclose sensitive information.


10) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-43158)

CWE-ID: CWE-664 - Improper control of a resource through its lifetime

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 improper state management in the xfs extended attribute leaf block freemap adjustment code when adding extended attributes to leaf blocks. A local user can set a crafted extended attribute to cause a denial of service.

The issue can corrupt free space accounting so that the name area overlaps the end of the entries array, triggering an assertion and shutting down the filesystem.


11) Race condition (CVE-ID: CVE-2026-43198)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/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 a race condition in tcp_v6_syn_recv_sock() when handling IPv6 TCP connection requests. A remote attacker can send network traffic that triggers the race to cause a denial of service.

The issue occurs because a child socket may become visible in the TCP ehash table before its IPv6 state is fully initialized.


12) Out-of-bounds write (CVE-ID: CVE-2026-43125)

CWE-ID: CWE-787 - Out-of-bounds write

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 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().


13) Improper input validation (CVE-ID: CVE-2026-46243)

CWE-ID: CWE-20 - Improper input validation

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, modify data, or cause a denial of service.

The vulnerability exists due to improper input validation in the cifs.spnego key description handling in fs/smb/client/cifs_spnego.c when processing userspace-created cifs.spnego keys through request_key(2) or add_key(2). A local user can supply a crafted cifs.spnego description to disclose sensitive information, modify data, or cause a denial of service.

The issue arises because authority-bearing fields such as pid, uid, creduid, and upcall_target may be treated by cifs.upcall as kernel-originating inputs.


14) Use-after-free (CVE-ID: CVE-2026-46090)

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 use-after-free in the ALSA aloop peer runtime handling when processing a format-change stop during concurrent stream operations. A local user can trigger concurrent playback start and capture close operations to cause a denial of service.

The issue occurs because a stale peer substream pointer may be used after the capture runtime is detached or freed.


15) Double free (CVE-ID: CVE-2026-45852)

CWE-ID: CWE-415 - Double 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 double free in rxe_srq_from_init in the RDMA rxe subsystem when handling a failed copy_to_user operation during SRQ creation. A local user can trigger an error path to cause a denial of service.


16) Race condition (CVE-ID: CVE-2026-46181)

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: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 race condition in mlx4_srq_event() when handling RDMA SRQ events. A local user can trigger an event for a partially initialized srq object to cause a denial of service.

The issue can occur if an event is delivered before the srq object has finished initializing.


Remediation

Install update from vendor's website.