SB20260921195 - SUSE update for the Linux Kernel



SB20260921195 - SUSE update for the Linux Kernel

Published: September 21, 2026

Security Bulletin ID SB20260921195
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 9
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 22% Low 78%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 9 vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2026-46116)

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 __xfrm_state_delete when deleting xfrm_state list entries during xfrm_state lifecycle handling. A local user can trigger repeated deletion of the same xfrm_state object to cause a denial of service.

The issue was reproduced under syzkaller load during network namespace cleanup in the xfrm subsystem.


2) Out-of-bounds read (CVE-ID: CVE-2026-52955)

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 access in crush_decode() when processing a CEPH_MSG_OSD_MAP message containing a crush map with mismatched bucket algorithm fields. A remote attacker can send a specially crafted CEPH_MSG_OSD_MAP message to cause a denial of service.


3) Out-of-bounds write (CVE-ID: CVE-2026-53059)

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

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 write in create_log_context() and dm-log bitset handling when processing a crafted device-mapper mirror target configuration with an oversized region count. A local user can create a crafted mirror target to cause a denial of service.

The issue is triggered when region_count overflows 32 bits, causing bitsets to be allocated smaller than required and later accessed with indices derived from the full region space.


4) NULL pointer dereference (CVE-ID: CVE-2026-53163)

CWE-ID: CWE-476 - NULL Pointer Dereference

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 null pointer dereference in remove_waiter() in the rtmutex futex proxy locking path when handling FUTEX_CMP_REQUEUE_PI operations during deadlock detection or proxy lock acquisition. A local user can invoke crafted futex operations to cause a denial of service.


5) 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.


6) Use-after-free (CVE-ID: CVE-2026-68121)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause memory corruption.

The vulnerability exists due to a use-after-free in pppoe_sendmsg() when handling a blocked send while a non-Ethernet port is added to an empty team device. A local user can trigger skb head reallocation and subsequent writes through a stale PPPoE header pointer to cause memory corruption.

The issue occurs because device header callbacks may reallocate the skb head and invalidate saved pointers into it.


7) Use-after-free (CVE-ID: CVE-2026-68202)

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 the ALSA sequencer queue timer handling in snd_seq_timer_delete() and related queue destruction logic when accessing /dev/snd/seq and re-opening a queue timer during queue teardown. A local user can issue crafted sequencer operations to leave a timer instance live and trigger a dereference of freed queue memory to cause a denial of service.

No queue ownership is required.


8) Use-after-free (CVE-ID: CVE-2026-72389)

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 STP timer handling in the Linux kernel bridge subsystem when deleting a bridge while the topology change timer is armed on an administratively down bridge. A local user can trigger bridge topology change detection and delete the bridge to cause a denial of service.

The issue occurs because the IFF_UP check was missing in br_topology_change_detection().


9) Out-of-bounds write (CVE-ID: CVE-2026-80580)

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

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 execute arbitrary code.

The vulnerability exists due to an out-of-bounds write in the fbdev sysfs mode output handling in drivers/video/fbdev/core/fbsysfs.c when processing a long modelist for sysfs output. A local user can trigger sysfs mode listing with a sufficiently long modelist to execute arbitrary code.


Remediation

Install update from vendor's website.