{
  "cveId": "CVE-2026-64044",
  "url": "https://patchblox.com/security/cve/CVE-2026-64044",
  "summary": "CVE-2026-64044 is fixed in 20 products on 1 platform, first by ALAS2023-2026-1881, released June 22, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  ovpn: respect peer refcount in CMD_NEW_PEER erro...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ovpn: respect peer refcount in CMD_NEW_PEER error path  ovpn_nl_peer_new_doit()\u0027s error path calls ovpn_peer_release() directly rather than ovpn_peer_put(), bypassing the kref. The accompanying comment (\u0022peer was not yet hashed, thus it is not used in any context\u0022) holds for UDP but not for TCP.  For UDP, the ovpn_socket union uses the .ovpn arm and never points back at a peer; UDP encap_recv looks up peers via the not-yet-populated hashtables, so the new peer is unreachable until ovpn_peer_add() publishes it.  For TCP, ovpn_socket_new() sets ovpn_sock-\u003Epeer and ovpn_tcp_socket_attach() publishes ovpn_sock via rcu_assign_sk_user_data(). From that moment until ovpn_socket_release() detaches in the error path, the TCP fd is fully wired: userspace recvmsg / sendmsg / close / poll on the fd, as well as the strparser-driven ovpn_tcp_rcv() path, can reach the peer through sk_user_data -\u003E ovpn_sock-\u003Epeer and bump its refcount via ovpn_peer_hold().  ovpn_tcp_socket_wait_finish() (called inside ovpn_socket_release()) drains strparser and the tx work, but does not synchronize with userspace syscall callers that already hold a peer reference. If ovpn_nl_peer_modify() or ovpn_peer_add() returns an error while such a caller is in flight - notably an ovpn_tcp_recvmsg() blocked in __skb_recv_datagram() on peer-\u003Etcp.user_queue - the direct ovpn_peer_release() destroys the peer while the caller still holds the reference, and the eventual ovpn_peer_put() from that caller operates on freed memory.  Replace the direct destructor call with ovpn_peer_put() so the kref correctly defers destruction until the last reference is dropped. In the common case where no concurrent user is present, behaviour is unchanged: the kref hits zero immediately and ovpn_peer_release_kref() runs the same destructor.  With this conversion ovpn_peer_release() has no callers outside peer.c - ovpn_peer_release_kref() in the same translation unit is the only remaining user - so make it static and drop its declaration from peer.h.",
  "published": "2026-06-22T09:00:00Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00184,
  "epssPercentile": 0.08016,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "bpftool6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "bpftool6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-6.18.35-68.127",
      "release": "amzn 2023",
      "fixedVersion": "1:1.0-0.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-aarch64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-x86_64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-headers",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra-common",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.12-1",
      "fix": "DEBIAN-CVE-2026-64044",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64044",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "microvm-kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
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      "product": "perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    },
    {
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      "product": "python3-perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.35-68.127.amzn2023",
      "fix": "ALAS2023-2026-1881",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1881",
      "released": "2026-06-22T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}