{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  smb: client: fix UAF and buffer leak in cifs_check_trans2() for malformed secondary T2  When a valid primary TRANSACT2 response has been received (mid-\u003eresp_buf set, mid-\u003emultiRsp true) and a subsequent secondary response causes cifs_check_trans2() to return false -- either because the SMB header is invalid (malformed != 0) or because check2ndT2() rejects the PDU -- handle_mid() overwrites mid-\u003eresp_buf with the new buffer (leaking the primary buffer) and, because mid-\u003emultiRsp is set, skips the server-\u003esmallbuf/bigbuf NULL-out.  When the user thread frees mid-\u003eresp_buf, server-\u003esmallbuf or server-\u003ebigbuf is left dangling; the demux thread reuses it for the next packet, resulting in a use-after-free.  Combine both early-exit conditions and, when mid-\u003emultiRsp is already set, abort the pending transaction inline: set multiEnd, call dequeue_mid() with malformed=true, and return true so handle_mid() exits without touching mid-\u003eresp_buf or the server buffer pointers.",
  "id": "DEBIAN-CVE-2026-89637",
  "modified": "2026-09-14T08:47:33.266431183Z",
  "published": "2026-09-11T20:19:49.370Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-89637"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-89637"
  ]
}