CVE-2025-21760: Linux kernel · ndisc: extend RCU protection in ndisc_send_skb()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High.
Data as of 10 Nov 2026, 14:02 UTC
Sources agree
| CNA (Linux) | CVSS 3.1 | 8.1 |
|---|---|---|
| CISA-ADP | CVSS 3.1 | 7.8 |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel by extending RCU protection in the ndisc_send_skb() function. Users and administrators should apply the official Linux kernel updates that include this fix.
Description
CVE-2025-21760 is a use-after-free vulnerability in the Linux kernel's ndisc_send_skb() function. The issue arises because the function can be called without holding RTNL or RCU locks, potentially leading to unsafe memory access. The vulnerability has been addressed by acquiring rcu_read_lock() earlier to safely use dev_net_rcu() and prevent the use-after-free condition.
References
- git.kernel.org/stable/c/10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1 (opens in a new tab)
- git.kernel.org/stable/c/4d576202b90b1b95a7c428a80b536f91b8201bcc (opens in a new tab)
- git.kernel.org/stable/c/e24d225e4cb8cf108bde00b76594499b98f0a74d (opens in a new tab)
- git.kernel.org/stable/c/a9319d800b5701e7f5e3fa71a5b7c4831fc20d6d (opens in a new tab)
- git.kernel.org/stable/c/ae38982f521621c216fc2f5182cd091f4734641d (opens in a new tab)
- git.kernel.org/stable/c/789230e5a8c1097301afc802e242c79bc8835c67 (opens in a new tab)
- git.kernel.org/stable/c/04e05112f10354ffc3bb6cc796d553bab161594c (opens in a new tab)
- git.kernel.org/stable/c/ed6ae1f325d3c43966ec1b62ac1459e2b8e45640 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/03/msg00028.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-265688.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)