CVE-2026-52985 netdevsim: zero initialize struct iphdr in dummy sk_buff

What is CVE-2026-52985?

CVE-2026-52985 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

netdevsim: zero initialize struct iphdr in dummy sk_buff

Syzbot reports a KMSAN uninit-value originating from nsim_dev_trap_skb_build, with the allocation also being performed in the same function.

Fix this by calling skb_put_zero instead of skb_put to guarantee zero initialization of the whole IP header.

Weakness: CWE-908

Which versions are affected by CVE-2026-52985?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-52985?

Apply the vendor's patch.

Is CVE-2026-52985 being exploited?

There is no known exploitation of CVE-2026-52985 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-52985, DEBIAN-CVE-2026-52985, GHSA-mwcx-xf66-xwqm, ROOT-OS-UBUNTU-2204-CVE-2026-52985, ROOT-OS-UBUNTU-2404-CVE-2026-52985, UBUNTU-CVE-2026-52985.