SB2026050778 - Ubuntu update for linux
Published: May 7, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Use After Free (CVE-ID: CVE-2026-23273)
The vulnerability allows a local attacker to cause a denial of service.
The vulnerability exists due to a use-after-free in the macvlan component of the Linux kernel when handling network interface creation errors. A local attacker can send a specially crafted netlink message to trigger improper RCU grace period handling during macvlan device creation, leading to a use-after-free condition.
Exploitation does not require elevated privileges and can result in a system crash due to access of already freed memory in the kernel network stack.
2) Use-after-free (CVE-ID: CVE-2026-23231)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error within the nf_tables_addchain() function in net/netfilter/nf_tables_api.c. A local user can escalate privileges on the system.
3) Input validation error (CVE-ID: CVE-2026-23112)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to improper input validation within the nvmet_tcp_free_cmd_buffers() function in drivers/nvme/target/tcp.c. A local user can perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.