{
  "fix": "RHSA-2026:63134",
  "url": "https://patchblox.com/security/fix/linux/rhsa-2026-63134",
  "summary": "RHSA-2026:63134, released June 26, 2026, fixes 5 CVEs in osbuild-composer (version 134.1-10.el10_0). None of them is reported as exploited. Patch Radar priority: Urgent.",
  "platform": "linux",
  "type": "advisory",
  "title": "osbuild-composer security update",
  "released": "2026-06-26T16:15:55Z",
  "priority": "Urgent",
  "priorityTier": 2,
  "priorityReason": "Closes CVE-2026-39821, rated Critical",
  "supported": true,
  "cveCount": 5,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.01834,
  "maxCvss": 10,
  "vendorAdvisory": "https://access.redhat.com/errata/RHSA-2026:63134",
  "appliesTo": [
    {
      "product": "osbuild-composer",
      "productUrl": "https://patchblox.com/security/product/linux/osbuild-composer",
      "release": "RHEL 10",
      "fixedVersion": "134.1-10.el10_0",
      "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-2026-55677",
      "url": "https://patchblox.com/security/cve/CVE-2026-55677",
      "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": 0.00519,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-25681",
      "url": "https://patchblox.com/security/cve/CVE-2026-25681",
      "title": "Invoking  incorrect handling of character references in DOCTYPE nodes in golang.org/x/net/html",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.7,
      "epss": 0.00223,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-27136",
      "url": "https://patchblox.com/security/cve/CVE-2026-27136",
      "title": "Invoking  duplicate attributes can cause XSS in golang.org/x/net/html",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.7,
      "epss": 0.00223,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-42502",
      "url": "https://patchblox.com/security/cve/CVE-2026-42502",
      "title": "Invoking  incorrect handling of HTML elements in foreign content in golang.org/x/net/html",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 8.2,
      "epss": 0.00223,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-07T12:40:37Z"
}