What’s Vulnerable › Vulnerabilities

CVE-2025-21763: neighbour: use RCU protection in __neigh_notify()

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-02-27 · updated 2026-10-15
• Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: neighbour: use RCU protection in __neigh_notify() __neigh_notify() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF.

Affected products

• Linux kernel: from 2.6.25 before 5.4.291; from 5.5 before 5.10.235; from 5.11 before 5.15.179; from 5.16 before 6.1.129; from 6.2 before 6.6.79; from 6.7 before 6.12.16 — fixed in 5.10.235, 5.15.179, 5.4.291, 6.1.129, 6.12.16, 6.13.4

How to fix

Upgrade to a fixed version: Linux kernel 5.10.235, 5.15.179, 5.4.291, 6.1.129. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/1cbb2aa90cd3fba15ad7efb5cdda28f3d1082379
• https://git.kernel.org/stable/c/40d8f2f2a373b6c294ffac394d2bb814b572ead1
• https://git.kernel.org/stable/c/559307d25235e24b5424778c7332451b6c741159
• https://git.kernel.org/stable/c/784eb2376270e086f7db136d154b8404edacf97b
• https://git.kernel.org/stable/c/8666e9aab801328c1408a19fbf4070609dc0695a
• https://git.kernel.org/stable/c/becbd5850c03ed33b232083dd66c6e38c0c0e569
• https://git.kernel.org/stable/c/cdd5c2a12ddad8a77ce1838ff9f29aa587de82df
• https://git.kernel.org/stable/c/e1aed6be381bcd7f46d4ca9d7ef0f5f3d6a1be32
• https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
• https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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