# CVE-2025-21764

## Summary

- **CVE ID:** CVE-2025-21764
- **Severity:** HIGH
- **CVSS Score:** 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Feb 27, 2025
- **Last Modified:** Sep 8, 2026

## 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 — Linux (de09334b9326632bbf1a74bfd8b01866cbbf2f61)
- Linux — Linux (3.9)
- Linux — Linux (0)
- Linux — Linux (5.4.291)
- Linux — Linux (5.10.235)
- Linux — Linux (5.15.179)
- Linux — Linux (6.1.129)
- Linux — Linux (6.6.79)
- Linux — Linux (6.12.16)
- Linux — Linux (6.13.4)
- Linux — Linux (6.14)

## References

- [CNA](https://git.kernel.org/stable/c/96fc896d0e5b37c12808df797397fb16f3080879)
- [CNA](https://git.kernel.org/stable/c/c30893ef3d9cde8e7e8e4fd06b53d2c935bbccb1)
- [CNA](https://git.kernel.org/stable/c/b870256dd2a5648d5ed2f22316b3ac29a7e5ed63)
- [CNA](https://git.kernel.org/stable/c/3c2d705f5adf5d860aaef90cb4211c0fde2ba66d)
- [CNA](https://git.kernel.org/stable/c/9e0ec817eb41a55327a46cd3ce331a9868d60304)
- [CNA](https://git.kernel.org/stable/c/bbec88e4108e8d6fb468d3817fa652140a44ff28)
- [CNA](https://git.kernel.org/stable/c/cd1065f92eb7ff21b9ba5308a86f33d1670bf926)
- [CNA](https://git.kernel.org/stable/c/628e6d18930bbd21f2d4562228afe27694f66da9)
- [CVE](https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html)
- [CVE](https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html)
- [siemens-SADP](https://cert-portal.siemens.com/productcert/html/ssa-265688.html)
- [siemens-SADP](https://cert-portal.siemens.com/productcert/html/ssa-019113.html)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.26%
- **EPSS Percentile:** 17.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._