CVE intelligence and bounded remediation

CVE-2026-52996 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix durable fd leak on ClientGUID mismatch in durable v2 open ksmbd_lookup_fd_cguid() returns a ksmbd_file with its refcount incremented via ksmbd_fp_get(). parse_durable_handle_context() in the DURABLE_REQ_V2 case properly releases this reference on every path inside the ClientGUID-match branch, either by calling ksmbd_put_durable_fd() or by transferring ownership to dh_info->fp for a successful reconnect. However, when an entry exists in the global file table with the same CreateGuid but a different ClientGUID, the code simply falls through to the new-open path without dropping the reference obtained from ksmbd_lookup_fd_cguid(). Per MS-SMB2 section 3.3.5.9.10 ("Handling the SMB2_CREATE_DURABLE_HANDLE_REQUEST_V2 Create Context"), the server MUST locate an Open whose Open.CreateGuid matches the request's CreateGuid AND whose Open.ClientGuid matches the ClientGuid of the connection that received the request. If no such Open is found, the server MUST continue with the normal open execution phase. A CreateGuid hit with a ClientGUID mismatch is therefore the "Open not found" case: proceeding with a new open is…

Severity
Medium
CVSS
5.5 (3.1)
Published
2026-06-24
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-401

Affected products

  • linux / linux_kernel

Showing 1 representative product identities from 4 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.