{
  "cveId": "CVE-2026-89664",
  "url": "https://patchblox.com/security/cve/CVE-2026-89664",
  "summary": "CVE-2026-89664 is fixed in linux on 1 platform by DEBIAN-CVE-2026-89664 (version 7.2.6-1), released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  nfsd: release OPEN-decoded posix ACLs via op_rel...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  nfsd: release OPEN-decoded posix ACLs via op_release  nfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates refcounted struct posix_acl objects via posix_acl_alloc() and stores them in open-\u003Eop_pacl and open-\u003Eop_dpacl. These pointers must be released once the OPEN compound finishes.  When nfsd4_decode_open_claim4() returns a non-seqid-mutating error, the dispatcher short-circuits before op_func runs:      nfsd4_proc_compound()       if (op-\u003Estatus \u0026\u0026 op-\u003Eopnum == OP_OPEN)           op-\u003Estatus = nfsd4_open_omfg(...)               if (!seqid_mutating_err(ntohl(op-\u003Estatus)))                   return op-\u003Estatus;   /* nfsd4_open() never runs */       ...       opdesc-\u003Eop_release(\u0026op-\u003Eu)  /* must still release op_pacl/op_dpacl */  Before this change OP_OPEN had no .op_release in nfsd4_ops[], and the release pair lived inside nfsd4_open() at its out_err: label. On the short-circuit path nfsd4_open() is never invoked, so both posix_acl refs leak on every malformed OPEN compound that carries valid POSIX ACL createhow4 attributes.  Add nfsd4_open_release() and wire it as .op_release for OP_OPEN. posix_acl_release() is NULL-safe, so the single release site covers both the normal path and the nfsd4_open_omfg short-circuit. Remove the matching posix_acl_release() pair from nfsd4_open()\u0027s out_err: label to avoid double-releasing.  The compound loop has two encoding branches: nfsd4_encode_operation() for normal ops, and nfsd4_encode_replay() for v4.0 replayed ops. op_release was only called from nfsd4_encode_operation(), so resources attached to op-\u003Eu leak on the replay path.  Move the op_release() call out of nfsd4_encode_operation() and the replay branch, placing it after the if-else in nfsd4_proc_compound(). This gives a single call site in a fairly obviously-correct place, covering both the normal encoding and replay paths.",
  "published": "2026-09-11T20:19:52Z",
  "severity": "high",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00488,
  "epssPercentile": 0.42251,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-89664",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89664",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}