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A flaw in the Linux kernel's TCP code, tracked as  CVE-2026-98432 , affects Ubuntu, Red Hat Enterprise Linux (RHEL), and other Linux distributions. The kernel's own CVE team rates it 9.8 out of 10 on the CVSS scale. Anthropic said  on October 27 that its AI model wrote an exploit that uses the flaw to let a remote attacker with no credentials run commands as root on Linux servers with a multipath TCP listener. As of October 29, Ubuntu and RHEL have not released a fixed kernel. Red Hat, Amazon, Oracle, and SUSE score the flaw between 5.9 and 8.1, lower than the kernel team's 9.8. The flaw is a race condition in the code that sets up new IPv4 TCP connections. It can make the kernel read memory it has already freed, a bug type known as a use-after-free. The kernel fix  credits Anthropic researcher Xinyang Ge with reporting the bug. Neither the CVE record nor the fix mentions multipath TCP (MPTCP). The link between that feature and this bug comes from Anthropic'...

A newly disclosed critical flaw in the Linux kernel allows code inside a virtual machine to read memory on the host computer it runs on. A researcher demonstrated the leak against Vercel's live cloud sandboxes, and Vercel confirmed it. The flaw, now tracked as CVE-2026-99999 and nicknamed PwnEscape , is in the Linux kernel's networking code, not in any one cloud's setup, so it reaches the shared layer that cloud providers use to keep customers' workloads apart. It was found in a Vercel security challenge and reported privately before any public release, and there is no sign it has been used in a real attack. What the Researcher Showed Paulos Yibelo of the security firm pwn.ai found that specially made network packets sent from inside a virtual machine could do three things, he explained in a  technical write-up : read the host's memory, crash the host, and run code on it. All three come from the same kernel flaw. Vercel said in its  report on the challen...

Linux servers running KSMBD, the kernel's built-in SMB server, are exposed to two publicly reported remote code execution flaws rated 9.0 by  Trend Micro's Zero Day Initiative , with no fix yet in the mainline kernel. One of them, ZDI-CAN-33774, can be triggered before any network authentication. The other, ZDI-CAN-33549, requires the SMB Direct transport and an RDMA-capable network interface. ZDI-CAN-33549  is an integer underflow in KSMBD's SMB Direct path. A client can supply RDMA buffer descriptors in which the first is longer than the declared payload, causing the server's size counter to wrap and allowing a subsequent memory copy to overrun the end of an allocated buffer. It requires three things: an RDMA-capable interface (hardware or the rxe software driver), a writable KSMBD share, and a client negotiating SMB Direct. ZDI-CAN-33774  requires no authentication, exposing any server running KSMBD on port 445. The flaw is a race in how KSMBD assign...

A flaw in Linux's vhost subsystem lets a local user read and write kernel memory at will and become root across nearly a decade of kernel versions. In one virtualization setup, it lets an untrusted virtual machine write to the host's memory and hijack the program that runs the virtual machine. The bug is tracked as  CVE-2026-74580  and named Vghost . Tencent Zhuque Lab, which found the flaw, released a fix on August 3 and published a full write-up on October 12 with working demos of both attacks. There is no public sign it has been exploited yet. vhost is the part of the Linux kernel that speeds up network and other input/output for virtual machines and containers. A local user reaches it by opening a device node, usually /dev/vhost-net or /dev/vhost-vsock. On the host, the flaw gives an unprivileged user a reliable way to read and write any kernel address, bypass KASLR, and escalate to root. The attack is deterministic: it needs no memory grooming and ...

The Russian state-sponsored hacking group known as Turla has transformed its custom backdoor Kazuar into a modular peer-to-peer (P2P) botnet that's engineered for stealth and persistent access to compromised hosts. Turla, per the U.S. Cybersecurity and Infrastructure Security Agency (CISA), is assessed to be affiliated with Center 16 of Russia's Federal Security Service (FSB). It overlaps with activity traced by the broader cybersecurity community under the names ATG26, Blue Python, Iron Hunter, Pensive Ursa, Secret Blizzard (formerly Krypton), Snake, SUMMIT, Uroburos, Venomous Bear, Waterbug, and WRAITH. The hacking group is known for its attacks targeting government, diplomatic, and defense sectors in Europe and Central Asia, as well as endpoints previously breached by Aqua Blizzard (aka Actinium and Gamaredon) to support the Kremlin's strategic objectives. "This upgrade aligns with Secret Blizzard's broader objective of gaini...

A use-after-free in the Linux kernel's AF_UNIX socket subsystem can be used to escape a container and gain root on the host, security firm DepthFirst  said in research published September 22. The flaw, tracked as  CVE-2026-80521  (CVSS score: 7.8), was fixed upstream on August 6, but Ubuntu has not shipped the patch for its 26.04, 24.04, or 22.04 LTS releases. DepthFirst  released exploit code  targeting Ubuntu 26.04. Ubuntu's security tracker  lists the Linux package on 26.04 as "vulnerable, work in progress." The 24.04 and 22.04 releases are also affected through newer kernel packages, including those for AWS, Azure, and GCP workloads. No fix has shipped on any affected release. The flaw is not in CISA's Known Exploited Vulnerabilities catalog, and there are no confirmed reports of attacks using it. The vulnerability sits in the kernel's garbage collector for AF_UNIX sockets. That collector cleans up file descriptors passed between processes t...

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...

RefluXFS , a Linux kernel flaw disclosed on July 22 and tracked as CVE-2026-64600 , lets an unprivileged local user overwrite root-owned files on an XFS filesystem and gain persistent root access. Qualys said default installations of Red Hat Enterprise Linux and its derivatives, Fedora Server, and Amazon Linux can meet the conditions for exploitation. The company demonstrated the race against /etc/passwd and setuid-root binaries. The overwrite lands at the block layer. It survives a reboot and leaves the target's ownership, permissions, timestamps, and setuid bit untouched, so a modified setuid-root binary still runs as root. The fix was merged on July 16, and Linux vendors have begun shipping backported kernels. The patch traces the bug to Linux 4.11 in 2017: a Fixes: tag naming commit 3c68d44a2b49 and a stable backport request marked # v4.11 . Who is exposed Exploitation requires three conditions: The system runs Linux 4.11 or later without the RefluXFS fix....

A security researcher has released working exploit code for four Linux kernel flaws that each let a local user gain root, the highest level of access on a machine. Kernel maintainers have fixed all four over the past few weeks, so a system running an up-to-date kernel is not affected. But the exploit code is now public, and any machine still running an older kernel should be updated. The flaws are called DirtyAH6 , TUNderflow , PPPoEject , and DiagSpill . Researcher Asim Manizada found them and reported them to the Linux kernel security team in mid-July. He published a technical  write-up  with working exploits on September 18, after a coordinated hold with Linux distributions so the fixes could be released first. So far, there are no reports of the four being used in real-world attacks. The exploits are Manizada's own, are tuned to specific kernel builds, and can crash a machine, so they are meant for isolated test systems. Still, public exploit code raises the ris...

Fixed kernels for a use-after-free vulnerability in the Linux kernel's IPv4 TCP code are now available for Red Hat Enterprise Linux 8, 9, and 10, while Ubuntu's fixes for its three newest long-term-support releases remain in its opt-in testing channel with no date for a regular update. The flaw, tracked as CVE-2026-98432 , can be reached by a remote, unauthenticated attacker and can lead to remote code execution,  Red Hat  and  Canonical  said. The Linux kernel's own CVE team rates the flaw 9.8 out of 10 on the CVSS scale. Red Hat, which initially rated it Moderate at 5.9, has raised its score to 9.8 and now calls it Critical. The bug has been present since Linux 4.4, and the upstream fix landed in October. What the Flaw Is When a server accepts an IPv4 TCP connection, the kernel passes IP options from the incoming request to the new socket without copying them. If the client retransmits its connection request while another processor still rea...

It turns out that the root cause behind several previously disclosed speculative execution attacks against modern processors, such as Meltdown and Foreshadow , was misattributed to 'prefetching effect,' resulting in hardware vendors releasing incomplete mitigations and countermeasures. Sharing its findings with The Hacker News, a group of academics from the Graz University of Technology and CISPA Helmholtz Center for Information Security finally revealed the exact reason behind why the kernel addresses are cached in the first place, as well as presented several new attacks that exploit the previously unidentified underlying issue, allowing attackers to sniff out sensitive data. The new research explains microarchitectural attacks were actually caused by speculative dereferencing of user-space registers in the kernel, which not just impacts the most recent Intel CPUs with the latest hardware mitigations, but also several modern processors from ARM, IBM, and AMD — previou...

Containers revolutionized the development process, acting as a cornerstone for DevOps initiatives, but containers bring complex security risks that are not always obvious. Organizations that don’t mitigate these risks are vulnerable to attack.  In this article, we outline how containers contributed to agile development, which unique security risks containers bring into the picture – and what organizations can do to secure containerized workloads, going beyond DevOps to achieve  DevSecOps . Why did containers catch on so fast? Containers are, in many ways, the evolution of virtualization. The goal was to speed up the development process, creating a more agile route from development through to testing and implementation – a method that’s more lightweight than using full-blown virtual machines, anyway. At the core of this issue is application compatibility, as applications require certain versions of libraries – which could clash with the requirements of other applications. ...

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...

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...

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 ...

A cybersecurity researcher with Google Project Zero has released the details, and a proof-of-concept (PoC) exploit for a high severity vulnerability that exists in Linux kernel since kernel version 3.16 through 4.18.8. Discovered by white hat hacker Jann Horn, the kernel vulnerability (CVE-2018-17182) is a cache invalidation bug in the Linux memory management subsystem that leads to use-after-free vulnerability, which if exploited, could allow an attacker to gain root privileges on the targeted system. The use-after-free (UAF) vulnerabilities are a class of memory corruption bug that can be exploited by unprivileged users to corrupt or alter data in memory, enabling them to cause a denial of service (system crash) or escalate privileges to gain administrative access on a system. Linux Kernel Exploit Takes an Hour to Gain Root Access However, Horn says his PoC Linux kernel exploit made available to the public "takes about an hour to run before popping a root shell....

Researchers at the University of Massachusetts Amherst have demonstrated an attack that revives expired Visa contactless credit cards for real in-store purchases by rewriting the expiration date a point-of-sale (POS) terminal reads over near-field communication (NFC), without breaking any of the card's cryptography. The attack, which the researchers named " Zombie Card ," requires physical possession of the expired card or sustained NFC proximity to it, plus a man-in-the-middle (MitM) relay positioned between the card and the terminal. It also requires that the account remain open under the same primary account number (PAN), which is standard practice when an issuer sends a replacement card, and that the issuing bank not independently re-check the expiry during authorization. The paper's preliminary study spans five major US banks and tests general tampering with Europay, Mastercard, and Visa (EMV) transactions. Raja Hasnain Anwar, the lead author, told The Hac...

Proof-of-concept (PoC) exploit code has now been released for a recently patched security flaw in the Linux kernel that could allow for local privilege escalation (LPE). Dubbed DirtyDecrypt (aka DirtyCBC), the vulnerability was discovered and reported by the Zellic and V12 security team on May 9, 2026, only to be informed by the maintainers that it was a duplicate of a vulnerability that had already been patched in the mainline. "It's a rxgk pagecache write due to missing COW [copy-on-write] guard in rxgk_decrypt_skb," Zellic co-founder Luna Tong (aka cts and gf_256) said in a description shared on GitHub. Although the CVE identifier was not disclosed, the vulnerability in question is CVE-2026-31635 (CVSS score: 7.5) based on the fact that the NIST National Vulnerability Database (NVD) includes a link to the DirtyDecrypt PoC in its CVE record. "The specific fault sits in rxgk_decrypt_skb(), the function that decrypts an incoming sk_buff (socket buffer) on th...

Vulnerabilities discovered in Microsoft PatchGuard kernel protection could allow hackers to plant rootkits on computers running the company's latest and secure operating system, Windows 10. Researchers at CyberArk Labs have developed a new attack technique which could allow hackers to completely bypass PatchGuard, and hook a malicious kernel code (rootkits) at the kernel level. PatchGuard, or (or Kernel Patch Protection) is a software tool that has been designed to forbid the kernel of 64-bit versions of Windows OS from being patched, preventing hackers from running rootkits or executing malicious code at the kernel level. Dubbed GhostHook , the attack is what the CyberArk Labs researchers call the first attack technique that thwarts the defensive technology to bypass PatchGuard, though it requires a hacker to already be present on a compromised system and running code in the kernel. So, basically, this is a post-exploitation attack. "[GhostHook] is neither an ...

A new critical zero-day vulnerability has been discovered in the Linux kernel that could allow attackers to gain root level privileges by running a malicious Android or Linux application on an affected device. The critical Linux kernel flaw ( CVE-2016-0728 ) has been identified by a group of researchers at a startup named Perception Point. The vulnerability was present in the code since 2012, and affects any operating system with Linux kernel 3.8 and higher , so there are probably tens of millions of computers, both 32-bit and 64-bit, exposed to this flaw. However, the most bothersome part is that the problem affects Android versions KitKat and higher , which means about 66 percent of all Android devices are also exposed to the serious Linux kernel flaw. Impact of the Zero-Day Vulnerability An attacker would only require local access to exploit the flaw on a Linux server. If successfully exploited, the vulnerability can allow attackers to get root access ...