Linux Kernel Releases Security Updates for Information Disclosure Vulnerability

Successful exploitation of CVE‑2026‑46333 could allow local attackers to disclose sensitive system files on affected Linux systems

Threat ID:: CC-4786
Threat Severity:: Medium
Published:: 20 May 2026 3:29 PM

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Successful exploitation of CVE‑2026‑46333 could allow local attackers to disclose sensitive system files on affected Linux systems

Affected platforms

The following platforms are known to be affected:

Linux kernel

All versions:

Prior to 5.10.256
Prior to 5.15.207
Prior to 6.1.173
Prior to 6.6.139
Prior to 6.12.89
Prior to 6.18.31
Prior to 7.0.8

Threat details

Proof-of-Concept Exploit

Public proof‑of‑concept exploit code for CVE‑2026‑46333 (also referred to as ssh‑keysign‑pwn) is available. Exploitation is local‑only but may result in disclosure of sensitive files, including SSH host keys and password hashes.

The NHS England National CSOC assesses exploitation as highly likely.

Introduction

The Linux kernel project has released a security advisory to address a medium severity vulnerability in the Linux kernel. Successful exploitation could allow a local attacker to read sensitive files opened by privileged processes.

CVE‑2026‑46333 – "Improper access control / race condition in ptrace dumpability logic" vulnerability – CVSS v3.1 score: 5.5

Remediation advice

Affected organisations are encouraged to review the CVE-2026-46333: ptrace: slightly saner 'get_dumpable()' logic advisory and to apply the relevant kernel updates as soon as possible.

Definitive source of threat updates

https://lore.kernel.org/linux-cve-announce/2026051554-CVE-2026-46333-662a@gregkh/T/#u

CVE Vulnerabilities

Status Published

CVE-2026-46333

In the Linux kernel, the following vulnerability has been resolved: ptrace: slightly saner 'get_dumpable()' logic The 'dumpability' of a task is fundamentally about the memory image of the task - the concept comes from whether it can core dump or not - and makes no sense when you don't have an associated mm. And almost all users do in fact use it only for the case where the task has a mm pointer. But we have one odd special case: ptrace_may_access() uses 'dumpable' to check various other things entirely independently of the MM (typically explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for threads that no longer have a VM (and maybe never did, like most kernel threads). It's not what this flag was designed for, but it is what it is. The ptrace code does check that the uid/gid matches, so you do have to be uid-0 to see kernel thread details, but this means that the traditional "drop capabilities" model doesn't make any difference for this all. Make it all make a *bit* more sense by saying that if you don't have a MM pointer, we'll use a cached "last dumpability" flag if the thread ever had a MM (it will be zero for kernel threads since it is never set), and require a proper CAP_SYS_PTRACE capability to override.

Last edited: 20 May 2026 3:29 pm