CVE-2025-40003: Linux kernel · net: mscc: ocelot: Fix use-after-free caused by cyclic delayed work
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.17.0-1007.7~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 10:12 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 17% 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
Exploitation evidence
Disclosed: evidence found.
CVE published 18 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 that replaces cancel_delayed_work() with disable_delayed_work_sync() in the affected code to properly cancel and synchronize delayed work items before workqueue destruction. Users should apply the official Linux kernel security updates as provided by their distribution vendors, such as the Ubuntu security notice USN-8029-1. No additional mitigation steps are required beyond applying the official fix.
Description
A use-after-free (UAF) vulnerability was identified and fixed in the Linux kernel's mscc ocelot network driver. The issue arises from improper cancellation of a cyclic delayed work item, which can be rescheduled after the workqueue is destroyed, leading to a UAF condition. The fix replaces cancel_delayed_work() with disable_delayed_work_sync() to ensure proper cancellation and completion of executing work before deallocation. This vulnerability affects specific Linux kernel versions and has been addressed in a security update.
References
- ubuntu.com/security/CVE-2025-40003 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40003 (opens in a new tab)
- git.kernel.org/linus/bc9ea787079671cb19a8b25ff9f02be5ef6bfcf5 (opens in a new tab)
- git.kernel.org/stable/c/70acdd1eb35ffb3afdcb59e4c3bbb178da411d0f (opens in a new tab)
- git.kernel.org/stable/c/bc9ea787079671cb19a8b25ff9f02be5ef6bfcf5 (opens in a new tab)
- git.kernel.org/stable/c/c3363db5d0685a8d077ade706051bbccc75f7e14 (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)