Skip to content
OpenAdvisories
High ALSA-2026:89082 14 CVEs

Important: kernel-rt security, bug fix, and enhancement update

Published Oct 24, 2026 · Updated Oct 29, 2026

Ecosystem: AlmaLinux

Summary

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

* kernel: tcp: restrict SO_ATTACH_FILTER to priv users (CVE-2026-53236)
* kernel: fuse: re-lock request before replacing page cache folio (CVE-2026-53388)
* kernel: writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs() (CVE-2026-64378)
* kernel: net: gro: fix double aggregation of flush-marked skbs (CVE-2026-68136)
* kernel: net/packet: avoid fanout hook re-registration after unregister (CVE-2026-68338)
* kernel: net/iucv: fix use-after-free of a severed iucv_path (CVE-2026-68140)
* kernel: net/sched: serialize qdisc_rtab_list against concurrent get/put (CVE-2026-68138)
* kernel: ipvs: reload ip header after head reallocation (CVE-2026-68476)
* kernel: selinux: avoid sk_socket dereference in selinux_sctp_bind_connect() (CVE-2026-72242)
* kernel: mptcp: options: reset DSS fields in case of unexpected size (CVE-2026-80586)
* kernel: usb: usbfs: fix use-after-free of usb_device in usbdev_release() (CVE-2026-80824)
* kernel: smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions (CVE-2026-89638)
* kernel: net/iucv: filter frames in afiucv_hs_rcv() by ingress device (CVE-2026-81003)
* kernel: ipv4: validate checksum_start before completing checksum (CVE-2026-99999)

Bug Fix(es) and Enhancement(s):

* Backport 6785011f8b16 ("ipv4: validate checksum_start before completing checksum") [almalinux-8.10.z] (JIRA:AlmaLinux-280584)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Fixed packages 10

ReleasePackageFixed in
AlmaLinux · 8 kernel-rt 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-core 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-debug 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-debug-core 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-debug-devel 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-debug-modules 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-debug-modules-extra 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-devel 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-modules 4.18.0-553.178.1.rt7.519.el8_10
AlmaLinux · 8 kernel-rt-modules-extra 4.18.0-553.178.1.rt7.519.el8_10

Vulnerabilities 14

  • Critical 9.8
    CVE-2026-68136

    net: gro: fix double aggregation of flush-marked skbs

    In the Linux kernel, the following vulnerability has been resolved: net: gro: fix double aggregation of flush-marked skbs Commit 0ab03f353d36 ("net-gro: Fix GRO flush when receiving a GSO packet.") added a flush check to skb_gro_receive(), but skb_gro_receive…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • Critical 9.8
    CVE-2026-68476

    ipvs: reload ip header after head reallocation

    In the Linux kernel, the following vulnerability has been resolved: ipvs: reload ip header after head reallocation __ip_vs_get_out_rt() calls skb_ensure_writable() which may reallocate skb->head.

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu
  • Critical 9.8
    CVE-2026-80586

    mptcp: options: reset DSS fields in case of unexpected size

    In the Linux kernel, the following vulnerability has been resolved: mptcp: options: reset DSS fields in case of unexpected size A remote peer could send a malformed DSS with a wrong size, followed by another DSS or MPC + Data. In this case, the first suboptio…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • Critical 9.3
    CVE-2026-99999 Public exploit

    ipv4: validate checksum_start before completing checksum

    In the Linux kernel, the following vulnerability has been resolved: ipv4: validate checksum_start before completing checksum If a packet with bad checksum metadata gets into the ipv4 stack, skb_checksum_help can corrupt the network header and cause a bunch of…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • High 8.8
    CVE-2026-68140

    net/iucv: fix use-after-free of a severed iucv_path

    In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use-after-free of a severed iucv_path af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connection's iucv_path. When th…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu
  • High 8.1
    CVE-2026-81003

    net/iucv: filter frames in afiucv_hs_rcv() by ingress device

    In the Linux kernel, the following vulnerability has been resolved: net/iucv: filter frames in afiucv_hs_rcv() by ingress device afiucv_hs_rcv() selects a socket from iucv_sk_list by matching four 8-byte name fields in the transport header alone. No check is …

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • High 7.8
    CVE-2026-53388

    fuse: re-lock request before replacing page cache folio

    In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before replacing page cache folio fuse_try_move_folio() unlocks the request on entry but does not re-lock it on the success path. This means fuse_chan_abort() can end th…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu
  • High 7.8
    CVE-2026-64378

    writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()

    In the Linux kernel, the following vulnerability has been resolved: writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs() When a container exits, the following BUG_ON() is occasionally triggered: ========================================…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • High 7.8
    CVE-2026-68138 Public exploit

    net/sched: serialize qdisc_rtab_list against concurrent get/put

    In the Linux kernel, the following vulnerability has been resolved: net/sched: serialize qdisc_rtab_list against concurrent get/put qdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly linked list qdisc_rtab_list and a plain non-atomic 'int …

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • High 7.8
    CVE-2026-68338

    net/packet: avoid fanout hook re-registration after unregister

    In the Linux kernel, the following vulnerability has been resolved: net/packet: avoid fanout hook re-registration after unregister packet_set_ring() temporarily detaches a socket from packet delivery while reconfiguring its ring. It records the previous runni…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu
  • High 7.8
    CVE-2026-89638

    smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions

    In the Linux kernel, the following vulnerability has been resolved: smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions When a file has the setuid or setgid bit set and is written to, the VFS strips those bits and issues a …

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • High 7.5
    CVE-2026-72242

    selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()

    In the Linux kernel, the following vulnerability has been resolved: selinux: avoid sk_socket dereference in selinux_sctp_bind_connect() selinux_sctp_bind_connect() dereferences sk->sk_socket to pass a struct socket * to selinux_socket_bind() and selinux_socke…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu
  • Unscored —
    CVE-2026-53236

    tcp: restrict SO_ATTACH_FILTER to priv users

    In the Linux kernel, the following vulnerability has been resolved: tcp: restrict SO_ATTACH_FILTER to priv users This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel …

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • Unscored —
    CVE-2026-80824

    usb: usbfs: fix use-after-free of usb_device in usbdev_release()

    In the Linux kernel, the following vulnerability has been resolved: usb: usbfs: fix use-after-free of usb_device in usbdev_release() usbdev_release() drops its reference to the struct usb_device before draining the list of completed async URBs, but that drain…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux

References

  • report
    https://access.redhat.com/security/cve/CVE-2026-53236
  • report
    https://access.redhat.com/security/cve/CVE-2026-53388
  • report
    https://access.redhat.com/security/cve/CVE-2026-64378
  • report
    https://access.redhat.com/security/cve/CVE-2026-68136
  • report
    https://access.redhat.com/security/cve/CVE-2026-68138
  • report
    https://access.redhat.com/security/cve/CVE-2026-68140
  • report
    https://access.redhat.com/security/cve/CVE-2026-68338
  • report
    https://access.redhat.com/security/cve/CVE-2026-68476
  • report
    https://access.redhat.com/security/cve/CVE-2026-72242
  • report
    https://access.redhat.com/security/cve/CVE-2026-80586
  • report
    https://access.redhat.com/security/cve/CVE-2026-80824
  • report
    https://access.redhat.com/security/cve/CVE-2026-81003
  • report
    https://access.redhat.com/security/cve/CVE-2026-89638
  • report
    https://access.redhat.com/security/cve/CVE-2026-99999
  • report
    https://bugzilla.redhat.com/2492709
  • report
    https://bugzilla.redhat.com/2502255
  • report
    https://bugzilla.redhat.com/2507296
  • report
    https://bugzilla.redhat.com/2513163
  • report
    https://bugzilla.redhat.com/2513264
  • report
    https://bugzilla.redhat.com/2513293
  • report
    https://bugzilla.redhat.com/2513343
  • report
    https://bugzilla.redhat.com/2516417
  • report
    https://bugzilla.redhat.com/2524438
  • report
    https://bugzilla.redhat.com/2528642
  • report
    https://bugzilla.redhat.com/2532122
  • report
    https://bugzilla.redhat.com/2532515
  • report
    https://bugzilla.redhat.com/2553429
  • advisory
    https://errata.almalinux.org/8/ALSA-2026-89082.html