{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c",
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4b333aed69cfc2c8687b86b6a4364a0dffc16dd8",
              "status": "affected",
              "version": "d7fd1f98607f2cd358e583f9548bdf0173090a86",
              "versionType": "git"
            },
            {
              "lessThan": "add8d7fb04efe564193df73581889c62fc0016f1",
              "status": "affected",
              "version": "d7fd1f98607f2cd358e583f9548bdf0173090a86",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c99ea7855124ca1428a1e59c2b4590aaef34eacf",
              "versionType": "git"
            },
            {
              "lessThan": "7.3",
              "status": "affected",
              "version": "7.2.8",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c",
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.3"
            },
            {
              "lessThan": "7.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.3.*",
              "status": "unaffected",
              "version": "7.3.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.4-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3.2",
                  "versionStartIncluding": "7.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.4-rc1",
                  "versionStartIncluding": "7.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "7.2.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: hold a connection reference for each session channel\n\nksmbd_session_unregister() removes a session from the global and per-\nconnection tables before dropping the table reference. A concurrent\nreference holder can keep the session and its channel list alive after\nthose removals.\n\nConnection cleanup can no longer find the unpublished session to remove its\nchannels. Since a channel only stores a raw conn pointer, the connection\ncan be freed while another session reference holder is still accessing it,\nfor example during SMB3.1.1 binding or a procfs read.\n\nTake a connection reference when registering a channel and release it on\ninsertion failure, channel removal, or final session destruction. Keep the\nchannels and signing keys until the session is destroyed so a response can\nstill be signed after the session has been unregistered."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - register_session_channel() runs from smb2_sess_setup() after ksmbd_conn_handler_loop() queues an SMB2 SESSION_SETUP read from the TCP socket. That command stores the connection in chann-\u003econn without a reference; a later failing SESSION_SETUP calls ksmbd_session_unregister(), and ksmbd_conn_free() can free it while the channel still points at it.\nAC:H - ksmbd_session_unregister() drops an established session only after session_setup_reauth sets SMB2_SESSION_IN_PROGRESS because sess-\u003ekerberos_expiry has passed. The attacker\u0027s chann-\u003econn-\u003ecipher_type read is smb2_sess_setup()\u0027s SMB 3.1.1 binding arm, entered only when KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL is already set, immediately after ksmbd_session_lookup_slowpath(), with no delay the attacker can hold across __ksmbd_conn_release_work().\nPR:L - register_session_channel() writes chann-\u003econn only after ntlm_authenticate() or krb5_authenticate() succeeds, and the reauth path that unregisters a session which already has channels depends on kerberos_expiry set by ksmbd_krb5_authenticate(). A SESSION_SETUP rejected before authentication stores no channel.\nUI:N - The client sends the SESSION_SETUP that registers the channel, the failing reauth SESSION_SETUP that calls ksmbd_session_unregister(), and the TCP close that reaches ksmbd_server_terminate_conn() and ksmbd_conn_free().\nS:U - The freed object is a ksmbd_conn in the host kernel that serves this SMB session, so the corruption stays in that kernel security authority.\nC:H - __ksmbd_conn_release_work() kfree_sensitive()s the conn while the channel keeps the pointer. smb2_sess_setup() then reads chann-\u003econn-\u003ecipher_type, and show_proc_session() follows chan-\u003econn-\u003evals and inet_addr; reclaiming the slab lets those uses disclose the replacement object.\nI:H - show_proc_session() down_read()s chan-\u003econn-\u003esession_lock through the channel\u0027s raw pointer after the connection can already have been freed, writing the rwsem of whatever reused that slot. The use-after-free of ksmbd_conn is a heap write against that allocation.\nA:H - smb2_sess_setup()\u0027s read of chann-\u003econn-\u003ecipher_type and show_proc_session()\u0027s lock of chan-\u003econn-\u003esession_lock both use the ksmbd_conn after __ksmbd_conn_release_work() freed it, which oopses the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T16:57:40.367Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4b333aed69cfc2c8687b86b6a4364a0dffc16dd8"
        },
        {
          "url": "https://git.kernel.org/stable/c/add8d7fb04efe564193df73581889c62fc0016f1"
        }
      ],
      "title": "ksmbd: hold a connection reference for each session channel",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99277",
    "datePublished": "2026-11-07T14:08:46.710Z",
    "dateReserved": "2026-09-25T10:25:14.405Z",
    "dateUpdated": "2026-11-10T16:57:40.367Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}