Use of uninitialized resource in Linux kernel - CVE-2026-99030

Vulnerability identifier: #VU157465

CSH Severity: Low

CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-99030

CWE-ID: CWE-908

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to obtain potentially sensitive information from stale kernel memory transmitted in outgoing packets.

The vulnerability exists due to use of uninitialized buffer contents in skb_copy_and_csum_bits() when encountering unreadable packet fragments after copying only the linear portion of a packet. A remote attacker can inspect affected outgoing ICMP error messages or driver transmissions to obtain stale memory contents from portions of the destination buffer that were not filled.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-fde-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-aws-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-43.43
linux-realtime (Ubuntu package) - update to 7.0.0-43.43.1
linux-oracle (Ubuntu package) - update to 7.0.0-1016.18
linux-aws (Ubuntu package) - update to 7.0.0-1017.18
linux-gcp (Ubuntu package) - update to 7.0.0-1017.19
linux-azure (Ubuntu package) - update to 7.0.0-1020.21
linux-raspi (Ubuntu package) - update to 7.0.0-1023.23
linux-ibm (Ubuntu package) - update to 7.0.0-1018.18
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1016.18~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1017.19~24.04.1
linux-azure-fde-7.0 (Ubuntu package) - update to 7.0.0-1019.19~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1018.18
linux-gke (Ubuntu package) - update to 7.0.0-1010.11
linux-azure-fde (Ubuntu package) - update to 7.0.0-1019.19
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1017.18~24.04.1

• https://git.kernel.org/stable/c/39d1a6b601831237c6038b5e3ac8dbb883c1700a
• https://git.kernel.org/stable/c/5551399751e2c9f31e4f3428040985a07e79d9c2
• https://git.kernel.org/stable/c/5f19b9cfff79508e8cb09be40d014cb0807f3854
• https://git.kernel.org/stable/c/ab9414ed70bd783e902a85c350620dee269bcb2b

• Use of uninitialized resource in Linux kernel core
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0 and more
• Ubuntu update for linux-raspi