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NTAP-20261030-0009 — CVE-2026-53176 Linux Kernel Vulnerability in NetApp Products

Published 2026-10-30 · Updated 2026-10-30 · Status: Interim · Exploitation: Public · Severity: CRITICAL 9.8 · ONTAP affected: Yes

Official advisory: NTAP-20261030-0009 on security.netapp.com ↗. Affected versions, fixed releases, and workarounds live there — this page is a summary.

Product family: SolidFire / NetApp HCI · ONTAP · Brocade SAN firmware · Baseboard management controllers · NetApp Console / BlueXP · SnapCenter  |  ONTAP-relevant  |  highest CVSS: 9.8

CVEs in this advisory

What the CVE records say

CVE-2026-53176 — In the Linux kernel, the following vulnerability has been resolved: IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN In drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done() computes the login request payload length as wc->byte_len minus ISER_HEADERS_LEN with no lower bound, and login_req_len is a signed int. A remote iSER initiator can post a login Send work request carrying fewer than ISER_HEADERS_LEN (76) bytes, so the subtraction underflows and login_req_len becomes negative. isert_rx_login_req() then reads that negative length back into a signed int, takes size = min(rx_buflen, MAX_KEY_VALUE_PAIRS), and because the min() is signed it keeps the negative value; the value is then passed as the memcpy() length and sign-extended to a multi-gigabyte size_t. The copy into the 8192-byte login->req_buf runs far out of bounds and faults, crashing the target node. The login phase precedes iSCSI authentication, so no credentials are required to reach this path. Reject any login PDU shorter than ISER_HEADERS_LEN before the subtraction, mirroring the existing early return on a failed work completion, so login_req_len can never go negative. The upper bound was already safe: a posted login buffer cannot deliver more than ISER_RX_PAYLOAD_SIZE, so the difference stays at or below MAX_KEY_VALUE_PAIRS and the existing min() clamps it; only the missing lower bound needs to be added.

Impact

Successful exploitation of this vulnerability could lead to Denial of Service (DoS).

Affected products

References

What to do

  1. Check the affected products listed above against the official advisory's affected-versions table — that is where the exact ONTAP 9 release, ONTAP tool, or management product versions are named.
  2. If affected and a fixed release exists, plan the upgrade — see the ONTAP upgrade runbook.
  3. If exploitation is listed as "active", treat remediation as urgent and review exposure (management LIFs, ONTAP S3, SnapMirror endpoints).
  4. Harden in parallel: security hardening baseline and ransomware protection on ONTAP.

Related reading

Browse all ONTAP CVEs → · Security hub