CVE-2025-40075: Linux kernel · tcp_metrics: use dst_dev_net_rcu()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in 6.17.0-1007.7~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-1007.7~24.04.1, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 +6
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 28 Oct 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 to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-14.14?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1008.8?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and has been released as part of the Ubuntu security update USN-8029-1. Users of affected Linux Azure kernel versions should apply the official kernel updates to remediate this vulnerability. No additional mitigation steps are indicated beyond applying the vendor-provided patches.
Description
A vulnerability identified as CVE-2025-40075 in the Linux kernel's tcp_metrics component has been resolved by replacing three dst_dev() calls with a lockdep-enabled helper dst_dev_net_rcu(). This fix addresses a kernel defect affecting various Linux Azure kernel versions. The vulnerability has a CVSS score of 8.1, indicating a high severity impact on confidentiality, integrity, and availability. Multiple Linux kernel subsystems have been updated in the related Ubuntu security advisory USN-8029-1, which includes this fix among others.
References
- ubuntu.com/security/CVE-2025-40075 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40075 (opens in a new tab)
- git.kernel.org/linus/50c127a69cd6285300931853b352a1918cfa180f (opens in a new tab)
- git.kernel.org/stable/c/07613a95326ebad2d1b88d883cd72546025a4f3e (opens in a new tab)
- git.kernel.org/stable/c/50c127a69cd6285300931853b352a1918cfa180f (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-3 (opens in a new tab)