Integer underflow in Linux kernel - CVE-2026-74282

Vulnerability identifier: #VU142914

CSH Severity: Medium

CVSS v4: 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]

CVE-ID: CVE-2026-74282

CWE-ID: CWE-191

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an integer underflow in tipc_sk_conn_proto_rcv() when processing a CONN_MANAGER/CONN_ACK message. A remote attacker can send a specially crafted connection acknowledgment with an oversized ack count to cause a denial of service.

For a local connection, the connected peer socket can trigger the issue.

Linux kernel
Ubuntu
linux-nvidia (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux (Ubuntu package) - addressed in versions 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

• https://git.kernel.org/stable/c/1e2c956745777e6ffdee7f30da5935741c03ee1e
• https://git.kernel.org/stable/c/3388145d258cf2c4c98278e3987296007d30672e
• https://git.kernel.org/stable/c/3cfa3d8e0dc167850edeb5bf5a07757db83fd54e
• https://git.kernel.org/stable/c/47ed873e4ceda34098bd46d8e96b4bb13cad3a04
• https://git.kernel.org/stable/c/67e55b054bf8025658dc0e255057f2a6236416bd
• https://git.kernel.org/stable/c/96f91b8ae1a489b3eca137e7acf42cf985fb8939
• https://git.kernel.org/stable/c/ab3e10b44ba5411779aac7afd2477917dd77750f
• https://git.kernel.org/stable/c/b44bebdd32c9ff66ee2aebfc317ced44bedd9335

• Integer underflow in Linux kernel tipc
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0