In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to create a ptrace relationship, which allows local users to obtain root access by leveraging certain scenarios with a parent-child process relationship, where a parent drops privileges and calls execve (potentially allowing control by an attacker). One contributing factor is an object lifetime issue (which can also cause a panic). Another contributing factor is i
In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to create a ptrace relationship, which allows local users to obtain root access by leveraging certain scenarios with a parent-child process relationship, where a parent drops privileges and calls execve (potentially allowing control by an attacker). One contributing factor is an object lifetime issue (which can also cause a panic). Another contributing factor is incorrect marking of a ptrace relationship as privileged, which is exploitable through (for example) Polkit's pkexec helper with PTRACE_TRACEME. NOTE: SELinux deny_ptrace might be a usable workaround in some environments.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact | 78.00 |
| Exploitation signal(KEV listed) | ×1.50 |
| VPI | 100.00 |
VPI formula vpi-v1
Required Action
Apply updates per vendor instructions.
| Source | CVSS Version | Base Score | Severity | Vector String | Assessment Date |
|---|---|---|---|---|---|
| NVDNIST | 3.1 | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | 04/20/2026 |
| NVDNIST | 2.0 | 7.2 |
| AV:L/AC:L/Au:N/C:C/I:C/A:C |
| 04/20/2026 |