{
  "cveId": "CVE-2026-72380",
  "url": "https://patchblox.com/security/cve/CVE-2026-72380",
  "summary": "CVE-2026-72380 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-72380, released August 15, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "xen/pvcalls: bound backend response req_id before indexing rsp[]",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  xen/pvcalls: bound backend response req_id before indexing rsp[]  pvcalls_front_event_handler() takes req_id directly from the backend-supplied ring response and uses it to index the fixed-size bedata-\u003Ersp[] array for a memcpy() and a store, with no range check. A malicious or buggy backend can set req_id past PVCALLS_NR_RSP_PER_RING and drive an out-of-bounds write past the bedata allocation.  req_id was also declared int while the wire field rsp-\u003Ereq_id is u32, so a range check on the signed value alone is insufficient: a backend req_id of 0xffffffff becomes -1, passes a \u003E= PVCALLS_NR_RSP_PER_RING test and indexes bedata-\u003Ersp[-1]. Declare req_id as u32 so a single bound covers both ends.  A backend that sends an out-of-range req_id has violated the wire protocol, so rather than silently dropping the response, log once and stop trusting the backend: set bedata-\u003Edisabled. The event handler then ignores further responses, and the request paths that wait for a response return -EIO instead of blocking forever. This mirrors the fatal-error handling xen-netback uses (xenvif_fatal_tx_err()).  The pvcalls frontend currently trusts its backend, so this is not a classic-Xen security issue, but it matters for hardening PV frontends against malicious backends (confidential and disaggregated deployments).",
  "published": "2026-08-15T06:22:11Z",
  "severity": "Moderate",
  "cvss": 8.8,
  "cvssVector": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.0035,
  "epssPercentile": 0.28798,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72380",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-72380",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-72380",
      "released": "2026-08-15T22:38:55Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.5-1",
      "fix": "DEBIAN-CVE-2026-72380",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-72380",
      "released": "2026-08-15T22:38:55Z"
    }
  ],
  "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"
  }
}