SB2026052310 - Ubuntu update for linux-lowlatency-hwe-5.15
Published: May 23, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Use After Free (CVE-ID: CVE-2026-23351)
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 the netfilter nft_set_pipapo component when handling a large number of expired elements during commit-time garbage collection. A local user can trigger prolonged non-preemptible execution to cause a denial of service.
Exploitation requires triggering garbage collection under a large number of expired elements, leading to soft lockup warnings and RCU stall reports.
2) Exposure of resource to wrong sphere (CVE-ID: CVE-2026-23274)
CWE-ID: CWE-668 - Exposure of resource to wrong sphere
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/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 input validation in the netfilter xt_IDLETIMER module when processing timer rules with reused labels. A local user can insert a revision 0 IDLETIMER rule with a label that was previously used by a revision 1 rule with XT_IDLETIMER_ALARM, leading to modification of an uninitialized timer_list object, which can trigger debugobjects warnings and potentially cause a kernel panic when panic_on_warn=1 is enabled.
Exploitation requires the ability to load netfilter rules. The impact is limited to denial of service via system crash under specific kernel configurations.
3) Improper locking (CVE-ID: CVE-2024-50060)
CWE-ID: CWE-667 - Improper Locking
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 perform a denial of service (DoS) attack.
The vulnerability exists due to improper locking within the __io_cqring_overflow_flush() function in io_uring/io_uring.c. A local user can perform a denial of service (DoS) attack.
4) Use-after-free (CVE-ID: CVE-2024-35862)
CWE-ID: CWE-416 - Use After Free
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 remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error within the smb2_is_network_name_deleted() function in fs/smb/client/smb2ops.c. A remote non-authenticated attacker can perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.