Kernel Security | Breaking Cybersecurity News | The Hacker News

A use-after-free bug in Linux's SCTP networking code can be turned into full root on a host, and Tencent researchers say they used it to escape a container and reach the machine underneath. The flaw has existed since 2008. The fix already shipped: stable kernels 7.1.6, 6.18.42, 6.12.101 and 6.6.148, released August 3, close it. Anyone running an older kernel with SCTP reachable should update. Tracked as  CVE-2026-64564  and named SCTPhantom by its finders, the flaw was disclosed publicly on August 6, two days after the kernel CVE team assigned it. No public exploit code had surfaced at the time of writing, and The Hacker News found no entry for the flaw in CISA's Known Exploited Vulnerabilities catalog as of August 7. The flaw is local, not remote, and it needs SCTP reachable on the target, which limits exposure. Where those conditions held, Tencent Zhuque Lab reports it got root on the kernel builds it tested for Debian 13, Ubuntu 24.04, Rocky Linux 9 and RHEL 9, and ...

Zapscape , a new Linux kernel vulnerability, could allow an attacker with kernel privileges inside an L1 guest virtual machine (VM) to escape KVM isolation and execute code on the host. The risk applies when nested virtualization is exposed to untrusted guests. The flaw is tracked as  CVE-2026-64561  and affects KVM/x86's shadow memory management unit (MMU), which manages shadow page tables used for nested guest memory translation. Security researcher Hyunwoo Kim, who disclosed the bug, said the demonstrated exploit path can run commands on the host with kernel, or root, privileges. The upstream fix has been merged, and administrators running KVM hosts that expose nested virtualization to untrusted guests should update to a fixed stable kernel or a vendor package that backports the patch. The required L1 kernel privilege usually means guest root. Intel systems also require both EPT page-walk length 4 and 5 to be exposed to the L1 guest. AMD has no equivalent conditio...

An unprivileged Linux program can time a hardware interrupt to land in the gap between a processor sanitizing its branch predictor and the kernel using it, re-poisoning the predictor after the defense has run. MIT CSAIL researchers Daniël Trujillo and Mengjia Yan named the technique INTERRUPT INJECTION . On an AMD Zen 2 machine running Linux 6.14 with every default Spectre v2 mitigation on, their exploit leaked arbitrary kernel memory at 5.47 bytes per second with 91.97% accuracy, enough to locate and read /etc/shadow, which stores the system's password hashes, in five of ten attempts. It needs no privileges, only local code execution, so the risk sits on shared systems running an affected processor. The pair disclosed to AMD and Intel on February 5. AMD told them it plans a kernel patch; MIT says one has since shipped and arrives in a normal operating system update. A fix is in the Linux kernel. The commit, "x86/bugs: Make Safe-RET robust against interrupt inject...

A memory corruption flaw in the Linux kernel's Open vSwitch datapath gives ordinary local users a path to root on a broad set of default-configured distributions, and a public exploit ships with pre-built records for roughly 800 kernel builds. The vulnerability, tracked as CVE-2026-64531 (CVSS score: 7.8) and codenamed OVSwrap by its discoverer, was disclosed by security researcher Asim Manizada on July 28, 2026. The bug sits in the kernel datapath, not the userspace ovs-vswitchd daemon. In a technical write-up , Manizada said an attacker needs "no existing OVS bridge, no running ovs-vswitchd, no host-level CAP_NET_ADMIN." On affected systems where the OVS kernel datapath is available and unprivileged user namespaces are enabled, an ordinary user can create private user and network namespaces with unshare -Urn, gain CAP_NET_ADMIN inside that namespace, and reach the vulnerable flow-installation path. If the openvswitch module is installed but not loaded, resolvi...

STAR Labs has published a Linux kernel exploit that turns an ordinary local user into root on the CentOS Stream 9 build it targeted. The flaw, tracked as CVE-2026-53264 (CVSS score: 7.8), is a use-after-free race in the kernel's network traffic-control subsystem. Researcher Lee Jia Jie said artificial intelligence (AI) helped him find the bug and speed up exploit development. This is local privilege escalation, not remote code execution, so an attacker needs a foothold on the machine before any of it applies. The demonstrated exploit also requires unprivileged user namespaces, the CONFIG_NET_ACT_GACT and CONFIG_NET_CLS_FLOWER kernel options, and a kernel-specific return-oriented programming (ROP) chain containing hardcoded offsets. Those conditions narrow the immediate exposure, but full exploit source code is now public. The upstream fix landed on June 1, 2026, and has since been backported to several stable kernel branches. The Linux CNA record lists vulnerable ranges begi...

Researchers at  Nebula Security  have disclosed GhostLock ( CVE-2026-43499 ), a 15-year-old Linux kernel flaw that lets any logged-in user take full root control of a machine that has not been patched. The vulnerable code has shipped by default in essentially every mainstream distribution since 2011. The flaw needs no special permission, no unusual settings, and no network access; ordinary threading calls from any local program are enough. Nebula turned it into a working root exploit that is 97% reliable in its testing and also escapes containers, and says Google awarded the team $92,337 through its  kernelCTF  bug-bounty program. No one is known to be exploiting it in the wild, but Nebula has published  working exploit code , so anyone can now run it. Patching is the priority. How the bug works The kernel has a system for keeping an urgent task from getting stuck behind a trivial one. Part of it is a cleanup step that tidies up after a task...

A use-after-free bug in Linux's KVM hypervisor can be triggered from a guest virtual machine to corrupt the shadow-page state of the host kernel that runs it. Dubbed ' Januscape ' and tracked as  CVE-2026-53359 , the flaw sits in the shadow MMU code that KVM shares across both Intel and AMD. The public proof-of-concept panics the host; the researcher claims that a separate, unreleased exploit turns the same bug into full host code execution. Security researcher  Hyunwoo Kim (@v4bel) found and reported the bug. He described Januscape as the first guest-to-host exploit triggerable on both Intel and AMD, to the best of public knowledge. The flaw went unnoticed for roughly 16 years. According to Kim, the exploit was used as a zero-day submission in  Google's kvmCTF , the controlled KVM vulnerability reward program that offers up to $250,000 for full guest-to-host escapes. How It Works To run a virtual machine, KVM keeps its own private set of page tables that mi...

DirtyClone is a new Linux kernel privilege escalation in the DirtyFrag family. JFrog Security Research published a working exploit walkthrough for the flaw on June 25, the first public demonstration for this variant. Tracked as  CVE-2026-43503  (CVSS 8.8), it lets a local user corrupt file-backed memory through a cloned network packet and gain root. The patch landed in mainline on May 21; if your kernel does not have it, update now. When the kernel copies a network packet internally, two helper functions drop a safety flag that marks the packet's memory as shared with a file on disk. That missing flag is the entire vulnerability. The attacker loads a privileged binary like /usr/bin/su into memory, wires those memory pages into a network packet, and forces the kernel to clone it. The cloned packet passes through an IPsec tunnel that the attacker controls, and the decryption step overwrites the binary's login checks with attacker-chosen bytes. The next time anyo...

Threat actors associated with Qilin  and Warlock ransomware operations have been observed using the bring your own vulnerable driver ( BYOVD ) technique to silence security tools running on compromised hosts, according to findings from Cisco Talos and Trend Micro. Qilin attacks analyzed by Talos have been found to deploy a malicious DLL named "msimg32.dll," which initiates a multi-stage infection chain to disable endpoint detection and response (EDR) solutions. The DLL, launched via DLL side-loading, is capable of terminating more than 300 EDR drivers from almost every security vendor in the market. "The first stage consists of a PE loader responsible for preparing the execution environment for the EDR killer component," Talos researchers Takahiro Takeda and Holger Unterbrink said . "This secondary payload is embedded within the loader in an encrypted form." The DLL loader implements an array of techniques to evade de...

Cybersecurity researchers have disclosed multiple security vulnerabilities within the Linux kernel's AppArmor module that could be exploited by unprivileged users to circumvent kernel protections, escalate to root, and undermine container isolation guarantees. The nine confused deputy vulnerabilities have been collectively codenamed CrackArmor by the Qualys Threat Research Unit (TRU). The cybersecurity company said the issue has existed since 2017. No CVE identifiers have been assigned to the shortcomings. AppArmor is a Linux security module that provides mandatory access control (MAC) and secures the operating system against external or internal threats by preventing known and unknown application flaws from being exploited. It has been included in the mainline Linux kernel since version 2.6.36. "This 'CrackArmor' advisory exposes a confused deputy flaw allowing unprivileged users to manipulate security profiles via pseudo-files, bypass user-namespace restricti...

The Chinese hacking group known as Mustang Panda (aka HoneyMyte) has leveraged a previously undocumented kernel-mode rootkit driver to deliver a new variant of backdoor dubbed TONESHELL in a cyber attack detected in mid-2025 targeting an unspecified entity in Asia. The findings come from Kaspersky, which observed the new backdoor variant in cyber espionage campaigns mounted by the hacking group targeting government organizations in Southeast and East Asia, primarily Myanmar and Thailand. "The driver file is signed with an old, stolen, or leaked digital certificate and registers as a minifilter driver on infected machines," the Russian cybersecurity company said . "Its end-goal is to inject a backdoor trojan into the system processes and provide protection for malicious files, user-mode processes, and registry keys." The final payload deployed as part of the attack is TONESHELL, an implant with reverse shell and downloader capabilities to fetch next-stage malwa...

Threat actors have been exploiting a security vulnerability in Paragon Partition Manager's BioNTdrv.sys driver in ransomware attacks to escalate privileges and execute arbitrary code. The zero-day flaw (CVE-2025-0289) is part of a set of five vulnerabilities that was discovered by Microsoft, according to the CERT Coordination Center (CERT/CC). "These include arbitrary kernel memory mapping and write vulnerabilities, a null pointer dereference, insecure kernel resource access, and an arbitrary memory move vulnerability," CERT/CC said . In a hypothetical attack scenario, an adversary with local access to a Windows machine can exploit these shortcomings to escalate privileges or cause a denial-of-service (DoS) condition by taking advantage of the fact that "BioNTdrv.sys" is signed by Microsoft. This could also pave the way for what's called a Bring Your Own Vulnerable Driver ( BYOVD ) attack on systems where the driver is not installed, thereby allowing t...