CVE-2025-40170: Linux kernel · net: use dst_dev_rcu() in sk_setup_caps()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in a805729c0091073d8f0415cfa96c7acd1bc17a48 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-06-16.
- Patch
- Available – fixed in a805729c0091073d8f0415cfa96c7acd1bc17a48, 99a2ace61b211b0be861b07fbaa062fca4b58879, 9f22b5f7f1a32f8bbcc82bf34e34ea63523fcd02 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade Linux kernel to a805729c0091073d8f0415cfa96c7acd1bc17a48, 99a2ace61b211b0be861b07fbaa062fca4b58879, 9f22b5f7f1a32f8bbcc82bf34e34ea63523fcd02 or 5d1be493d1110c9e720b4c51a6e587bb2fb4ac12.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: net: use dst_dev_rcu() in sk_setup_caps() Use RCU to protect accesses to dst->dev from sk_setup_caps() and sk_dst_gso_max_size(). Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(), and ip_dst_mtu_maybe_forward(). ip4_dst_hoplimit() can use dst_dev_net_rcu().
References
- git.kernel.org/stable/c/9f22b5f7f1a32f8bbcc82bf34e34ea63523fcd02 (opens in a new tab)
- git.kernel.org/stable/c/5d1be493d1110c9e720b4c51a6e587bb2fb4ac12 (opens in a new tab)
- git.kernel.org/stable/c/a805729c0091073d8f0415cfa96c7acd1bc17a48 (opens in a new tab)
- git.kernel.org/stable/c/99a2ace61b211b0be861b07fbaa062fca4b58879 (opens in a new tab)