ZeroHour

Search: “linuxFile”

27 items

Smart search ranks by meaning as well as keywords (one row per story, last 45 days).

ZDI-26-698: Linux Kernel NTFS3 Out-Of-Bounds Read Information Disclosure Vulnerability

ZDI-26-698: Linux Kernel NTFS3 out-of-bounds read (CVSS 5.2) allows local attackers to disclose sensitive information on affected systems.

ZDI advisory ZDI-26-698 describes an out-of-bounds read in the Linux Kernel NTFS3 driver rated CVSS 5.2. Exploitation requires the attacker to first obtain the ability to execute low-privileged code on the target. The impact is limited to local information disclosure. No CVE identifier is listed in the advisory.

USN-8730-1: Linux kernel vulnerability

Ubuntu issued USN-8730-1 fixing Linux kernel flaws in IPv6 networking and Netfilter that could allow system compromise.

Ubuntu released USN-8730-1 addressing a security issue discovered in the Linux kernel. The update corrects flaws in the IPv6 networking and Netfilter subsystems. Ubuntu states an attacker could possibly use the issue to compromise the system.

Ubuntu Security Notices · 9d agoAdvisory 6 sources

Suspected China-Nexus Actor Exploits VMware vCenter Flaw, Deploys Babuk

QUIRSO attributes exploitation of VMware vCenter CVE-2026-59310 to a suspected China-nexus actor that hit 361 IPs in 47 countries, deploying backdoors and Babuk.

German incident response firm QUIRSOS assessed with moderate confidence that a suspected China-nexus actor, likely operating in UTC+08:00 hours, exploited VMware vCenter flaw CVE-2026-59310 (CVSS 9.8 directory traversal) beginning five days after Broadcom's July 29 patch. The campaign compromised 361 unique victim IPs across 47 countries, most in Germany, the US, Turkey, Iran, and France. The actor abused cron jobs, a XOR-obfuscated 'linuxFile' WebSocket backdoor with systemd/cron persistence, a JSP web shell, SSH authorized-keys manipulation, and a reverse SSH tool, with one Babuk deployment reported. A separate vCenter 'vcenter_admin' account creation consistent with CVE-2026-59309 exploitation was also observed from August 1.

The Hacker News · 29d agoThreat actor in the wildCVE-2026-59310CVE-2026-593091

PoisonedRefresh: A Fileless Linux Rootkit That Injects PHP Web Shells Into F5 BIG-IP APM Server Memory

Sophos details PoisonedRefresh, a fileless Linux rootkit that injects a memory-resident PHP web shell into F5 BIG-IP APM after exploitation of CVE-2025-53521.

On September 8, 2026, SophosLabs published an analysis of Linux/Agnt-IC (dubbed PoisonedRefresh by ESET) found in compromised F5 BIG-IP Access Policy Manager environments. Initial access leverages CVE-2025-53521, an unauthenticated RCE in BIG-IP APM when an access policy is configured on a virtual server; F5 confirmed exploitation and links the activity to cluster c05d5254, while Shadowserver observed 795 exposed vulnerable endpoints. A first stage hidden in a modified umount binary modifies /usr/sbin/httpd and SELinux configuration and embeds itself in BIG-IP upgrade images for persistence. The second-stage ELF intercepts __libc_start_main, hooks apr_dso_load, and injects a PHP web shell into libphp memory via mmap manipulation, leaving no disk artifacts, and exposes a /bin/bash shell via a local UNIX domain socket instead of a TCP port.

Security Affairs · 7d agoMalware in the wildCVE-2025-53521

Re: Linux kernel LPEs: ZcopyReaper (CVE-2026-43502) and 20 more

oss-security thread discusses newly disclosed Linux kernel local privilege escalations, including ZcopyReaper (CVE-2026-43502) and about 20 more flaws.

An oss-security mailing list thread discusses newly disclosed Linux kernel local privilege escalation (LPE) issues, headlined by ZcopyReaper (CVE-2026-43502) along with roughly 20 more. Discussants ask whether the many reports could be summarized and note that locking kernel module loading after boot has repeatedly proven an effective mitigation. The visible discussion does not state whether any of the flaws are exploited in the wild or give specific patch guidance beyond the individual reports.

oss-security · 7d agoVulnerabilityCVE-2026-43502

Re: Vulnerability fixes in util-linux-2.42.3

util-linux 2.42.3 includes vulnerability fixes, with a commit link shared for downstream tracking but no CVEs cited.

An oss-security post links a util-linux commit (286dd3ff41526b582ef48830de239dffbaa61f90) as part of the 2.42.3 vulnerability fix release. No CVE identifiers, flaw descriptions, or exploitation details are provided. The item is a routine open-source fix notification for downstream distributors.

oss-security · 10d agoVulnerability1

Linux Foundation takes on TRACE, a hardware-backed runtime evidence specification for AI agents

The Linux Foundation adopts TRACE, an OPAQUE-contributed spec giving AI agents hardware-attested, cryptographically verifiable runtime and compliance evidence.

The Linux Foundation accepted the TRACE (Trust, Runtime Attestation and Compliance Evidence) specification contributed by OPAQUE, developed with AMD, Intel, Microsoft, and the Technology Innovation Institute. TRACE binds runtime environment, software, policies, data classifications, and tool usage into a portable, cryptographically verifiable artifact, composing existing standards such as RATS, EAT, SLSA, SCITT, SPIFFE, and EAR. It recorded nearly 135,000 PyPI downloads within 10 weeks of its June 2026 introduction, and its technical workstream will be hosted by the Coalition for Secure AI.

Help Net Security · 21d agoAI tools & infra

TPMSpy: Validation of Measured Boot Systems by Low-Level Tracing of TPM Usage

Researchers present TPMSpy, a platform-agnostic method validating TPM Measured Boot via low-level tracing, finding inconsistent Linux systemd measurements that break remote attestation and LUKS decryption.

An arXiv paper (2609.05011) introduces TPMSpy, a method that analyzes virtualized system–TPM interactions to independently reconstruct and validate TPM Event Logs without relying on the quoting mechanism, applicable to open and closed systems and demonstrated on Linux and Windows. A longitudinal analysis of Linux systems running systemd versions 245–258 (2020–2025) found wide divergence in Measured Boot usage, undocumented behavioral changes, and no common usage pattern. The authors report inconsistent measurement of user-space systemd services, which prevents reliable remote attestation and LUKS disk decryption on affected systems.

arXiv cs.CR · 11d agoResearch

Hackers deploy Linux rootkit on F5 BIG-IP APM devices, hiding web shell in memory

Sophos analyzed a Linux rootkit, tracked as PoisonedRefresh, on hacked F5 BIG-IP APM devices hiding an in-memory web shell linked to exploited CVE-2025-53521.

Sophos and ESET analyzed an implant (named PoisonedRefresh by ESET) deployed on compromised F5 BIG-IP APM appliances, which serves enterprise, financial, government, and public sector deployments. The second-stage payload intercepts __libc_start_main, hooks Apache's APR module loader (apr_dso_load), RC4-encodes key strings, and rewrites PHP file reads in memory to embed a web shell inside legitimate scripts like apm_css.php3, full_wt.php3, and webtop_popup_css.php3, leaving on-disk files unchanged. A related installer component infects /usr/sbin/httpd, persists across BIG-IP upgrade images, modifies SELinux configuration, and deploys the payload. The malware also creates a Unix domain socket at /run/bigtlog.pipe that hands authenticated local connections to /bin/bash; F5 links the activity to CVE-2025-53521, an unauthenticated RCE in BIG-IP APM already exploited in the wild.

Help Net Securityupdated · 5d agofirst · 6d agoMalware in the wild 2 sourcesCVE-2025-535211

Linux Detection Engineering - Fileless Execution

Elastic Security Labs reproduces five Linux fileless execution patterns, including memfd_create staging and in-memory kernel module loads, and maps each to Elastic Defend rules.

Elastic Security Labs reproduced five Linux fileless execution patterns using its FENIX tooling: memfd_create staging, interpreter one-liners, deleted binaries, and in-memory kernel module loads. Each pattern is mapped to the Elastic Defend detection rules that catch it. The post is part of the team's ongoing Linux detection engineering series.

Elastic Security Labs · 14d agoResearch

Backdoor Xz Utils Linux Open Source

Infosecurity Magazine covers the XZ Utils open-source backdoor, a malicious implant in liblzma that targeted OpenSSH on major Linux distributions.

The article covers the XZ Utils backdoor, a malicious implant introduced into the widely used open-source compression library. The compromised liblzma code manipulated functions used by OpenSSH, nearly reaching stable releases of major Linux distributions before discovery. The incident is a prominent example of software supply chain compromise targeting critical open-source infrastructure.

Infosecurity Magazine · Aug 17, 2026VulnerabilityCVE-2024-3094

Re: Linux kernel LPEs: ZcopyReaper (CVE-2026-43502) and 20 more

Linux kernel developers discuss a batch of 21 local privilege escalation CVEs, including ZcopyReaper (CVE-2026-43502) in the RDS networking driver.

An oss-security thread examines newly published Linux kernel local privilege escalation issues tracked in the kernel.org security vulnerabilities git repository. CVE-2026-43502, dubbed ZcopyReaper, affects the net/rds (Reliable Datagram Sockets) subsystem. The discussion references roughly 20 additional kernel LPE CVEs published in the 2026 Q3 window.

oss-security · 7d agoVulnerabilityCVE-2026-43502

ZDI-26-696: Linux Kernel NTFS3 Journal Heap-based Buffer Overflow Code Execution Vulnerability

ZDI-26-696: Linux Kernel NTFS3 journal heap-based buffer overflow (CVE-2026-72196, CVSS 8.8) enables local arbitrary code execution.

ZDI advisory ZDI-26-696 describes a heap-based buffer overflow in the Linux Kernel NTFS3 journal handling, tracked as CVE-2026-72196 with a CVSS score of 8.8. Exploitation requires the attacker to first execute low-privileged code on the target system. Successful exploitation allows local attackers to execute arbitrary code. No in-the-wild exploitation is mentioned.

Linux Foundation Introduces TRACE Standard for AI Runtime Evidence

The Linux Foundation introduced TRACE, an open standard providing hardware-attested runtime and compliance evidence for AI agents.

The Linux Foundation announced TRACE, an open standard designed to generate hardware-attested runtime evidence for AI agents. The standard aims to give auditors and regulators verifiable proof of what AI agents actually executed. It targets compliance and assurance needs for organizations deploying autonomous AI systems.

Infosecurity Magazine · 21d agoAI tools & infra1

Linux kernel LPEs: ZcopyReaper (CVE-2026-43502) and 20 more

Researchers disclosed CVE-2026-43502 (ZcopyReaper), a Linux kernel local privilege escalation in the RDS zerocopy send path, fixed in v7.1-rc3.

Yuan Tan reported a Linux kernel local privilege escalation in the RDS zerocopy send path, tracked as CVE-2026-43502 and dubbed ZcopyReaper, posted to oss-security. The flaw was introduced in Linux v4.17 and fixed by commit 44b550d88b26, first appearing in mainline v7.1-rc3. The researchers demonstrated local privilege escalation on an openSUSE system running kernel 6.4.0-150600.23.100. The post also references 20 additional Linux kernel LPEs, though CVE ids were not provided in the excerpt.

oss-security · 8d agoVulnerabilityCVE-2026-43502

Cpython: [CVE-2026-82049] tarfile extraction filters allow file modification and content disclosure via hard link to symlink

Python discloses CVE-2026-82049: tarfile extraction filters can be bypassed via hard links to symlinks, enabling file modification and content disclosure.

Stan Ulbrych disclosed CVE-2026-82049 on the Python security-announce list, forwarded to oss-security by Alan Coopersmith. The flaw affects CPython's tarfile extraction filters, which can allow file modification and content disclosure when archives contain a hard link to a symlink. Extraction-filter misuse can therefore bypass intended protections during archive unpacking.

oss-security · 1d agoVulnerabilityCVE-2026-82049

Debian 13.7 ships the fixes behind 92 security advisories, updates 106 packages

Debian 13.7 'trixie' point release bundles 92 security advisories and 106 package updates, including kernel, glibc, u-boot and qemu fixes.

Debian shipped version 13.7 of 'trixie', folding in 92 previously published security advisories and corrections to 106 source packages, including six Linux kernel advisories (DSA-6381, DSA-6393, DSA-6405, DSA-6415, DSA-6466, DSA-6477). glibc fixes a buffer overflow (CVE-2026-5928) and buffer underflow (CVE-2026-5450), with 17 packages rebuilt against the updated library; qemu carries 25 CVEs including a secure boot bypass (CVE-2026-16288), imagemagick 24, wolfssl 15 and perl 13. Boot-chain fixes include a u-boot FIT image verification bypass (CVE-2026-46728), a BOOTP/DHCP buffer overread (CVE-2024-42040), and corrected intermediate certificate verification in sbsigntool. The installer was rebuilt with kernel ABI 6.12.107+deb13, and existing systems receive the fixes through normal package mirror updates.

ZDI-26-572: Linux Kernel XFRM Race Condition Local Privilege Escalation Vulnerability

ZDI publishes ZDI-26-572, a CVSS 7.5 race condition local privilege escalation in the Linux kernel's XFRM subsystem.

The Zero Day Initiative disclosed a race condition in the Linux kernel's XFRM (transform) subsystem allowing local attackers to escalate privileges. Exploitation requires the attacker to first run high-privileged code on the affected system. The advisory carries a CVSS rating of 7.5; no CVE id is listed in the disclosure text.

ZDI Published Advisories · Aug 13, 2026Advisory

ZDI-26-693: Linux Kernel ksmbd Share Configuration Race Condition Remote Code Execution Vulnerability

ZDI-26-693: authenticated race condition in Linux kernel ksmbd share configuration allows remote code execution on ksmbd-enabled systems; CVSS 8.5.

ZDI advisory ZDI-26-693 discloses a race condition in the Linux kernel's ksmbd share configuration that allows remote attackers to execute arbitrary code on affected installations. Exploitation requires authentication, and only systems with ksmbd enabled are vulnerable. ZDI assigned a CVSS rating of 8.5; no CVE is listed in the advisory text.

ZDI Published Advisories · 2d agoVulnerability1

'TerminalFix' Campaign Weaponizes PowerShell for Enterprise Attacks

A ClickFix-style campaign called TerminalFix weaponizes PowerShell and reverse tunnels to infiltrate enterprise networks in a multistage attack chain.

Dark Reading reports on the TerminalFix campaign, a sophisticated multistage attack targeting enterprises. It uses a ClickFix-style social engineering lure and heavily weaponizes PowerShell. The chain establishes reverse tunnels into victim organizations' networks, giving operators interactive access for follow-on activity.

Dark Reading · 15d agoThreat actor in the wild

Hackers breach F5 BIG-IP APM devices to deploy Linux rootkit

Sophos analyzed a Linux rootkit on F5 BIG-IP APM devices that injects a fileless PHP web shell, likely after CVE-2025-53521 exploitation.

Sophos analyzed a Linux rootkit targeting F5 BIG-IP APM environments, also tracked by ESET as PoisonedRefresh, which hijacks Apache's apr_dso_load module loader to inject a fileless PHP web shell into memory. The implant intercepts __libc_start_main, hides strings with RC4, creates a password-protected local UNIX socket backdoor for interactive Bash access, and persists across BIG-IP upgrade images while modifying SELinux configuration. It is likely a second-stage payload following exploitation of CVE-2025-53521, a critical RCE flaw F5 reclassified from a DoS issue in March. The ShadowServer Foundation tracked 795 F5 BIG-IP APM endpoints exposed online.

BleepingComputer · 7d agoMalware in the wildCVE-2025-53521

Exclusive: Linux Foundation's Akrites to Go Live in September

The Linux Foundation's Akrites initiative will go live in September, accepting AI-powered vulnerability reports for open-source projects.

The Linux Foundation's Akrites initiative will become operational in September 2026, when it begins accepting AI-powered vulnerability reports for open-source projects. The launch was exclusively reported by Infosecurity Magazine. The program is aimed at handling vulnerability disclosures across the foundation's open-source ecosystem using AI capabilities.

Infosecurity Magazine · 27d agoTools

Linux Kernel ZcopyReaper Vulnerability Lets Local Attackers Gain Root Privileges

Linux kernel RDS zero-copy flaw CVE-2026-43502 (ZcopyReaper) lets unprivileged local users gain root; fix in 7.1-rc3, public PoC published.

CVE-2026-43502, dubbed ZcopyReaper, is a Linux kernel local privilege escalation flaw in the RDS zerocopy send path, present since kernel 4.17, allowing unprivileged local attackers to gain root. NebuSec researcher Yuan Tan demonstrated root escalation on openSUSE kernel 6.4.0-150600.23.100; the fix landed in commit 44b550d88b26 with Linux 7.1-rc3 the first patched mainline release. Exploitation requires CONFIG_RDS and CONFIG_RDS_TCP but not unprivileged user namespaces, and PoC exploit material is publicly released alongside more than 20 other exploitable 2026 kernel CVEs.

ZDI-26-686: Linux Kernel nftables Race Condition Local Privilege Escalation Vulnerability

ZDI discloses CVE-2026-74565, a CVSS 7.8 nftables race condition letting local low-privileged attackers escalate privileges on Linux.

ZDI-26-686 describes a race condition in the Linux Kernel nftables subsystem that allows local attackers to escalate privileges. Exploitation requires the ability to execute low-privileged code on the target system. ZDI assigned a CVSS rating of 7.8 and CVE-2026-74565.

Linux Detection Engineering - Local Privilege Escalation

Elastic details a layered detection framework for Linux local privilege escalation, covering 2026's copy-on-write bug wave and LLM-assisted discovery.

Elastic Security Labs describes how most Linux local privilege escalations share a common host flow — an unprivileged process launched from a writable path becoming root — and proposes layered detections combining general outcome-based rules with per-technique rules in Elastic Defend and Auditd. It tracks 13 recent LPE disclosures, seven of which share a copy-on-write/zero-copy bug class, including Copy Fail, DirtyFrag, Fragnesia, DirtyDecrypt, DirtyClone, pedit COW, and RefluXFS. Qualys attributes RefluXFS to an LLM-assisted research effort with Anthropic using Claude Mythos Preview, and another bug is credited to an LLM-assisted workflow. Detection and endpoint rules are published in Elastic's detection-rules and protections-artifacts repositories.

Elastic Security Labs · 5d agoResearch

USN-8736-1: Perl vulnerabilities

Ubuntu issued USN-8736-1 fixing two Perl regex flaws that could cause denial of service, code execution, or security-restriction bypass.

Ubuntu released a security notice addressing two Perl vulnerabilities in regular expression handling. CVE-2026-15534 involves mishandling of large inputs during regex matching, enabling out-of-bounds heap reads or writes that could lead to denial of service or arbitrary code execution. CVE-2026-19487 involves incorrect matching for regexes with alternative branches, allowing security restrictions to be bypassed. Users are advised to apply the updated packages.