{
  "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:  usb: atm: usbatm: fix invalid ci_range initialization  syzbot reported a shift-out-of-bounds in __vcc_connect():    UBSAN: shift-out-of-bounds in net/atm/common.c:382:32   shift exponent -1 is negative   CPU: 0 UID: 0 PID: 5987 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)   Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026   Call Trace:    \u003cTASK\u003e    dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120    ubsan_epilogue+0xa/0x30 lib/ubsan.c:233    __ubsan_handle_shift_out_of_bounds+0x36d/0x400 lib/ubsan.c:494    __vcc_connect+0x14b4/0x19c0 net/atm/common.c:382    vcc_connect+0x328/0x8f0 net/atm/common.c:498    pvc_bind+0x272/0x380 net/atm/pvc.c:52    __sys_bind+0x2e3/0x410 net/socket.c:1976    __x64_sys_bind+0x7a/0x90 net/socket.c:1979    ...  ATM device ci_range fields (vpi_bits and vci_bits) represent the number of bits supported for VPI and VCI addressing on the device. net/atm/common.c directly uses these fields as bit shift counts:   vpi \u003e\u003e dev-\u003eci_range.vpi_bits   vci \u003e\u003e dev-\u003eci_range.vci_bits   1 \u003c\u003c vcc-\u003edev-\u003eci_range.vpi_bits   1 \u003c\u003c vcc-\u003edev-\u003eci_range.vci_bits  usbatm_atm_init() sets ci_range.vpi_bits and ci_range.vci_bits to ATM_CI_MAX (-1), which is defined in \u003cuapi/linux/atmdev.h\u003e as a sentinel value for userspace ATM_SETCIRANGE requests, not a valid bit count. Shifting by -1 is undefined behavior and triggers UBSAN warnings.  ATM UNI cell headers allow up to 8 bits for VPI (0..255) and 16 bits for VCI (0..65535). Initialize vpi_bits to 8 and vci_bits to 16, as done by solos-pci.",
  "id": "DEBIAN-CVE-2026-90055",
  "modified": "2026-09-18T04:47:35.460199127Z",
  "published": "2026-09-17T17:16:54.020Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-90055"
    }
  ],
  "upstream": [
    "CVE-2026-90055"
  ]
}