CVE intelligence and bounded remediation

CVE-2026-4209 — Dlink Dnr-202L Firmware security vulnerability

Critical CVSS 9.8

A vulnerability was identified in D-Link DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05 and DNS-1550-04 up to 20260205. Affected is the function cgi_create_import_users/cgi_user_batch_create/cgi_user_set_quota/cgi_user_del/cgi_user_modify/cgi_group_set_quota/cgi_group_modify/cgi_group_add/cgi_user_add/cgi_get_modify_group_info/cgi_chg_admin_pw of the file /cgi-bin/account_mgr.cgi. The manipulation leads to command injection. It is possible to initiate the attack remotely. The exploit is publicly available and might be used.

Severity
Critical
CVSS
9.8 (3.1)
Published
2026-03-16
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-74, CWE-77

Affected products

  • dlink / dnr-202l_firmware
  • dlink / dnr-326_firmware
  • dlink / dns-1100-4_firmware
  • dlink / dns-120_firmware
  • dlink / dns-1200-05_firmware
  • dlink / dns-1550-04_firmware

Showing 6 representative product identities from 20 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

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

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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