{
  "fix": "RLSA-2026:66016",
  "url": "https://patchblox.com/security/fix/linux/rlsa-2026-66016",
  "summary": "RLSA-2026:66016, released September 10, 2026, fixes 10 CVEs in osbuild-composer (version 0:101.5-2.el8_10.rocky.0.6). None of them is reported as exploited. Patch Radar priority: Urgent.",
  "platform": "linux",
  "type": "advisory",
  "title": "osbuild-composer security update",
  "released": "2026-09-10T06:01:40Z",
  "priority": "Urgent",
  "priorityTier": 2,
  "priorityReason": "Closes CVE-2026-39821, rated Critical",
  "supported": true,
  "cveCount": 10,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.01834,
  "maxCvss": 10,
  "vendorAdvisory": "https://errata.rockylinux.org/RLSA-2026:66016",
  "appliesTo": [
    {
      "product": "osbuild-composer",
      "productUrl": "https://patchblox.com/security/product/linux/osbuild-composer",
      "release": "rocky 8",
      "fixedVersion": "0:101.5-2.el8_10.rocky.0.6",
      "supported": true
    }
  ],
  "cves": [
    {
      "cveId": "CVE-2026-39821",
      "url": "https://patchblox.com/security/cve/CVE-2026-39821",
      "title": "Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna",
      "priority": "Urgent",
      "severity": "Critical",
      "cvss": 10,
      "epss": 0.01834,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-39820",
      "url": "https://patchblox.com/security/cve/CVE-2026-39820",
      "title": "Quadratic string concatentation in consumeComment in net/mail",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00784,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2024-45336",
      "url": "https://patchblox.com/security/cve/CVE-2024-45336",
      "title": "osbuild-composer: A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild under the hood",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.2,
      "epss": 0.0071,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-33818",
      "url": "https://patchblox.com/security/cve/CVE-2026-33818",
      "title": "Enforce maximum recursion depth in encoding/asn1",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.8,
      "epss": 0.00568,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-56853",
      "url": "https://patchblox.com/security/cve/CVE-2026-56853",
      "title": "Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/http",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.8,
      "epss": 0.00568,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-56859",
      "url": "https://patchblox.com/security/cve/CVE-2026-56859",
      "title": "Add recursion depth guard during decode in encoding/xml",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00568,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-56862",
      "url": "https://patchblox.com/security/cve/CVE-2026-56862",
      "title": "Limit handshake messages we are willing to accept post-handshake in crypto/tls",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00568,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-56860",
      "url": "https://patchblox.com/security/cve/CVE-2026-56860",
      "title": "Avoid quadratic complexity in resolvePath in net/url",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.8,
      "epss": 0.0055,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-56858",
      "url": "https://patchblox.com/security/cve/CVE-2026-56858",
      "title": "Fix Javascript regexp context tracking in html/template",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.8,
      "epss": 0.0031,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2024-9355",
      "url": "https://patchblox.com/security/cve/CVE-2024-9355",
      "title": "osbuild-composer: A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild under the hood",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.2,
      "epss": 0.00298,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-07T06:34:28Z"
}