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)
Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - HSI subsystem; - I3C subsystem; - SMB network file system; - Padata parallel execution mechanism; - Timer subsystem; - Networking core; (CVE-2023-52854, CVE-2024-35867, CVE-2024-50061, CVE-2024-56664, CVE-2025-21727, CVE-2025-37838, CVE-2025-38352)
{
"binaries": [
{
"binary_version": "5.4.0-1056.59",
"binary_name": "linux-buildinfo-5.4.0-1056-iot"
},
{
"binary_version": "5.4.0-1056.59",
"binary_name": "linux-headers-5.4.0-1056-iot"
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{
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"binary_name": "linux-iot-headers-5.4.0-1056"
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{
"binary_version": "5.4.0-1056.59",
"binary_name": "linux-tools-5.4.0-1056-iot"
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],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2023-52854"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2024-35867"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2024-50061"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2024-56664"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "high",
"type": "Ubuntu"
}
],
"id": "CVE-2025-21727"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-37838"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "high",
"type": "Ubuntu"
}
],
"id": "CVE-2025-38352"
},
{
"severity": [
{
"score": "high",
"type": "Ubuntu"
}
],
"id": "CVE-2025-40300"
}
],
"ecosystem": "Ubuntu:Pro:20.04:LTS"
}