The most severe Linux threat to surface in years catches the world flat
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-31431 | Local Privilege Escalation (Copy Fail) in Linux Kernel algif_aead Interface CVE-2026-31431 ('Copy Fail') is an incorrect resource transfer between spheres (CWE-669/CWE-1288) in the Linux kernel's algif_aead implementation of the AF_ALG userspace crypto interface, introduced roughly nine years ago (around 2017, per public reporting) when commit 72548b093ee3 switched AEAD operations to in-place handling even though the source and destination buffers come from different mappings. A local, unprivileged user can trigger the flaw by performing AEAD operations through the AF_ALG socket interface, causing the kernel to mishandle the copy of ciphertext and associated data. Successful exploitation provides a reliable local privilege escalation to root (C:H/I:H/A:H per the CVSS vector). Nearly every major Linux distribution and enterprise platform is exposed, including the kernel itself, Red Hat Enterprise Linux (including AUS, EUS, TUS and Update Services for SAP Solutions), OpenShift Container Platform, Amazon Linux, Ubuntu, Debian, openSUSE Leap, SUSE CaaS Platform, NixOS, and Linux-based products from Arista and Siemens. The flaw has public proof-of-concept code, a 99.9% EPSS score, and was added to CISA's Known Exploited Vulnerabilities catalog on 2026-05-01, indicating exploitation in the wild (ransomware use is unknown). Do: Patch by installing the kernel update for CVE-2026-31431 through your distribution's security channel (Red Hat Enterprise Linux including AUS/EUS/TUS/SAP channels, OpenShift, Amazon Linux, Ubuntu, Debian, openSUSE Leap, SUSE CaaS Platform, NixOS, and Arista/Siemens firmware/software as applicable) and reboot into the patched kernel; the data provides no fixed version numbers, so defer to vendor advisories. Because the flaw is in CISA's KEV catalog (added 2026-05-01) with a 99.9% EPSS score, prioritize internet-reachable and multi-user systems first and follow BOD 22-01 guidance for cloud services. Check running kernel versions ('uname -r') and distribution advisory status to confirm you are on a fixed build. | 7.8 | 100% | KEV PoC ×5 |
| masshundreds of millions to billions of installations (servers, cloud instances, desktops, and Android/embedded devices running affected kernel generations) |
Full article285 words · extracted from arstechnica.com · click to collapse
Publicly released exploit code for an effectively unpatched vulnerability that gives root access to virtually all releases of Linux is setting off alarm bells as defenders scramble to ward off severe compromises inside data centers and on personal devices.
The vulnerability and exploit code that exploits it were released Wednesday evening by researchers from security firm Theori, five weeks after privately disclosing it to the Linux kernel security team. The team patched the vulnerability in versions 7.0, 6.19.12, 6.18.12, 6.12.85, 6.6.137, 6.1.170, 5.15.204, and 5.10.254) but few of the Linux distributions had incorporated those fixes at the time the exploit was released.
A single script hacks all distros
The critical flaw, tracked as CVE-2026-31431 and the name CopyFail, is a local privilege escalation, a vulnerability class that allows unprivileged users to elevate themselves to administrators. CopyFail is particularly severe because it can be exploited with a single piece of exploit code—released in Wednesday’s disclosure—that works across all vulnerable distributions with no modification. With that, an attacker can, among other things, hack multi-tenant systems, break out of containers based on Kubernetes or other frameworks, and create malicious pull requests that pipe the exploit code through CI/CD work flows.
“‘Local privilege escalation’ sounds dry, so let me unpack it,” researcher Jorijn Schrijvershof wrote Thursday. “It means: an attacker who already has some way to run code on the machine, even as the most boring unprivileged user, can promote themselves to root. From there they can read every file, install backdoors, watch every process, and pivot to other systems.”
Schrijvershof added that the same Python script Theori released works reliably for Ubuntu 22.04, Amazon Linux 2023, SUSE 15.6, and Debian 12. The researcher continued:
Text extracted automatically; images, tables and formatting may be missing. Original: https://arstechnica.com/security/2026/04/as-the-most-severe-linux-threat-in-years-surfaces-the-world-scrambles/