Use-after-free in Linux kernel - CVE-2026-90111

Vulnerability identifier: #VU151366

CSH Severity: Low

CVSS v4: 0 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90111

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to trigger a slab use-after-free.

The vulnerability exists due to a use-after-free in the IPv6 multicast routing cache reporting function ip6mr_cache_report() when resolving an unresolved multicast forwarding-cache entry after its associated route has been deleted and the queue is resolved with a wrong parent interface. A remote attacker can send an ingress multicast packet that misses multicast forwarding-cache lookup to trigger a wrong-parent-interface report.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.115-2

• https://git.kernel.org/stable/c/235b42b5860189eb8c27c36435ad932cae65a734
• https://git.kernel.org/stable/c/4a674afaae4136c71943aa3e35d433676fd40e8f

• Use-after-free in Linux kernel ipv6
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more