What’s Vulnerable › Vulnerabilities

CVE-2025-21764: ndisc: use RCU protection in ndisc_alloc_skb()

• 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: ndisc: use RCU protection in ndisc_alloc_skb() ndisc_alloc_skb() can be called without RTNL or RCU being held. Add RCU protection to avoid possible UAF.

Affected products

• Linux kernel: from 3.9 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/3c2d705f5adf5d860aaef90cb4211c0fde2ba66d
• https://git.kernel.org/stable/c/628e6d18930bbd21f2d4562228afe27694f66da9
• https://git.kernel.org/stable/c/96fc896d0e5b37c12808df797397fb16f3080879
• https://git.kernel.org/stable/c/9e0ec817eb41a55327a46cd3ce331a9868d60304
• https://git.kernel.org/stable/c/b870256dd2a5648d5ed2f22316b3ac29a7e5ed63
• https://git.kernel.org/stable/c/bbec88e4108e8d6fb468d3817fa652140a44ff28
• https://git.kernel.org/stable/c/c30893ef3d9cde8e7e8e4fd06b53d2c935bbccb1
• https://git.kernel.org/stable/c/cd1065f92eb7ff21b9ba5308a86f33d1670bf926
• 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-019113.html
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html

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