What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-24 · updated 2026-07-14
• Weakness: CWE-908

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.

Affected products

• Linux kernel: from 5.4 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.141; from 6.7 before 6.12.91; from 6.13 before 6.18.33 — fixed in 5.10.258, 5.15.209, 6.1.175, 6.12.91, 6.18.33, 6.6.141

How to fix

Upgrade to a fixed version: Linux kernel 5.10.258, 5.15.209, 6.1.175, 6.12.91. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/175556c049eaec14efde8c6475e763b7579b9de7
• https://git.kernel.org/stable/c/1b7b6ae0e93b8d512e208b1378d74af052e4f4e7
• https://git.kernel.org/stable/c/35eaa6d8d6c2ee65e96f507add856e0eacf24591
• https://git.kernel.org/stable/c/6e2cfd0904976e701d7a76b86b694e72af230ab0
• https://git.kernel.org/stable/c/750d0091bebf44975421268d37484ef87060d263
• https://git.kernel.org/stable/c/818f7673ed7f4a29d4b9cee8184c47d6e57162b4
• https://git.kernel.org/stable/c/978ca6ff789f1f19c03288ac20cc1f4774e88490
• https://git.kernel.org/stable/c/bc6002865e8c4fcf9e94975f7cf023448d8764e2

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