https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Sat, 03 Oct 2026 07:54:43 +0000 https://vulnerability.circl.lu/vuln/cve-2025-40300 <p><strong>Affected:</strong> Linux, Siemens SIMATIC CN 4100, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>x86/vmscape: Add conditional IBPB mitigation</p> <p>VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit.</p> <p>Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB.</p> <p>This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace.</p> <p>The intent is to integrate and optimize these cases post-embargo.</p> <p>[ dhansen: elaborate on suboptimal IBPB solution ]</p> <p><strong>Affected:</strong> Linux, Siemens SIMATIC CN 4100, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>x86/vmscape: Add conditional IBPB mitigation</p> <p>VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit.</p> <p>Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB.</p> <p>This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace.</p> <p>The intent is to integrate and optimize these cases post-embargo.</p> <p>[ dhansen: elaborate on suboptimal IBPB solution ]</p> https://vulnerability.circl.lu/vuln/cve-2025-40300 https://vulnerability.circl.lu/vuln/usn-7850-1 <p><strong>Affected:</strong> Ubuntu:Pro:14.04:LTS: linux</p> <p>Jean-Claude Graf, Sandro Rüegge, Ali Hajiabadi, and Kaveh Razavi discovered that the Linux kernel contained insufficient branch predictor isolation between a guest and a userspace hypervisor for certain processors. This flaw is known as VMSCAPE. An attacker in a guest VM could possibly use this to expose sensitive information from the host OS. (CVE-2025-40300)</p> <p>A security issues was discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystem: - USB sound devices; (CVE-2024-53150)</p> <p><strong>Affected:</strong> Ubuntu:Pro:14.04:LTS: linux</p> <p>Jean-Claude Graf, Sandro Rüegge, Ali Hajiabadi, and Kaveh Razavi discovered that the Linux kernel contained insufficient branch predictor isolation between a guest and a userspace hypervisor for certain processors. This flaw is known as VMSCAPE. An attacker in a guest VM could possibly use this to expose sensitive information from the host OS. (CVE-2025-40300)</p> <p>A security issues was discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystem: - USB sound devices; (CVE-2024-53150)</p> https://vulnerability.circl.lu/vuln/usn-7850-1