It was discovered that Tornado incorrectly handled special characters in HTTP headers. An attacker could possibly use this issue to execute a cross- site scripting (XSS) attack. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10. (CVE-2025-67724)
It was discovered that Tornado incorrectly handled repeated HTTP headers. An attacker could possibly use this issue to cause Tornado to use excessive resources, causing a denial of service. (CVE-2025-67725)
It was discovered that Tornado incorrectly handled parsing of certain HTTP header values. An attacker could possibly use this issue to cause Tornado to use excessive resources, causing a denial of service. (CVE-2025-67726)
{
"availability": "No subscription required",
"binaries": [
{
"binary_name": "python3-tornado",
"binary_version": "6.4.0-1ubuntu0.4"
}
]
}{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67724"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67725"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67726"
}
],
"ecosystem": "Ubuntu:24.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7950-1.json"
{
"availability": "No subscription required",
"binaries": [
{
"binary_name": "python3-tornado",
"binary_version": "6.4.2-3ubuntu0.2"
}
]
}{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67724"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67725"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67726"
}
],
"ecosystem": "Ubuntu:25.10"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7950-1.json"
{
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "python-tornado",
"binary_version": "4.2.1-1ubuntu3.1+esm2"
},
{
"binary_name": "python3-tornado",
"binary_version": "4.2.1-1ubuntu3.1+esm2"
}
]
}{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67725"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67726"
}
],
"ecosystem": "Ubuntu:Pro:16.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7950-1.json"
{
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "python-tornado",
"binary_version": "4.5.3-1ubuntu0.2+esm2"
},
{
"binary_name": "python3-tornado",
"binary_version": "4.5.3-1ubuntu0.2+esm2"
}
]
}{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67725"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67726"
}
],
"ecosystem": "Ubuntu:Pro:18.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7950-1.json"
{
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "python3-tornado",
"binary_version": "6.0.3+really5.1.1-3ubuntu0.1~esm3"
}
]
}{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67724"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67725"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67726"
}
],
"ecosystem": "Ubuntu:Pro:20.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7950-1.json"
{
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "python3-tornado",
"binary_version": "6.1.0-3ubuntu0.1~esm4"
}
]
}{
"cves": [
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67724"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67725"
},
{
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"id": "CVE-2025-67726"
}
],
"ecosystem": "Ubuntu:Pro:22.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7950-1.json"