{
  "cveId": "CVE-2025-39904",
  "url": "https://patchblox.com/security/cve/CVE-2025-39904",
  "summary": "CVE-2025-39904 is fixed in linux on 1 platform by DEBIAN-CVE-2025-39904 (version 6.16.8-1), released October 1, 2025. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  arm64: kexec: initialize kexec_buf struct in loa...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  arm64: kexec: initialize kexec_buf struct in load_other_segments()  Patch series \u0022kexec: Fix invalid field access\u0022.  The kexec_buf structure was previously declared without initialization.  commit bf454ec31add (\u0022kexec_file: allow to place kexec_buf randomly\u0022) added a field that is always read but not consistently populated by all architectures.  This un-initialized field will contain garbage.  This is also triggering a UBSAN warning when the uninitialized data was accessed:  \t------------[ cut here ]------------ \tUBSAN: invalid-load in ./include/linux/kexec.h:210:10 \tload of value 252 is not a valid value for type \u0027_Bool\u0027  Zero-initializing kexec_buf at declaration ensures all fields are cleanly set, preventing future instances of uninitialized memory being used.  An initial fix was already landed for arm64[0], and this patchset fixes the problem on the remaining arm64 code and on riscv, as raised by Mark.  Discussions about this problem could be found at[1][2].   This patch (of 3):  The kexec_buf structure was previously declared without initialization. commit bf454ec31add (\u0022kexec_file: allow to place kexec_buf randomly\u0022) added a field that is always read but not consistently populated by all architectures. This un-initialized field will contain garbage.  This is also triggering a UBSAN warning when the uninitialized data was accessed:  \t------------[ cut here ]------------ \tUBSAN: invalid-load in ./include/linux/kexec.h:210:10 \tload of value 252 is not a valid value for type \u0027_Bool\u0027  Zero-initializing kexec_buf at declaration ensures all fields are cleanly set, preventing future instances of uninitialized memory being used.",
  "published": "2025-10-01T08:15:33Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00134,
  "epssPercentile": 0.0295,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.16.8-1",
      "fix": "DEBIAN-CVE-2025-39904",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-39904",
      "released": "2025-10-01T08:15:33Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}