A vulnerability in the Calix EXOS firmware for the GS7 XGS (GS5239XG) residential router allows unauthenticated remote attackers to modify NAT port‑forwarding rules via the UPnP WANIPConnection service. The device exposes the MiniUPnPd control endpoint on the WAN interface on TCP port 5000 without access controls. A remote attacker can send crafted SOAP requests to add, delete, or enumerate port mappings, or to query the external IP address, without authentication. Successful exploitation may enable bypass of the firewall/NAT boundary and exposure of internal LAN services to the public internet.
History

Tue, 25 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-306
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 21 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Calix
Calix gs7 Xgs (gs5239xg)
Vendors & Products Calix
Calix gs7 Xgs (gs5239xg)

Fri, 21 Aug 2026 17:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-276
CWE-284

Fri, 21 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
References

Fri, 21 Aug 2026 15:00:00 +0000

Type Values Removed Values Added
Description A vulnerability in the Calix EXOS firmware for the GS7 XGS (GS5239XG) residential router allows unauthenticated remote attackers to modify NAT port‑forwarding rules via the UPnP WANIPConnection service. The device exposes the MiniUPnPd control endpoint on the WAN interface on TCP port 5000 without access controls. A remote attacker can send crafted SOAP requests to add, delete, or enumerate port mappings, or to query the external IP address, without authentication. Successful exploitation may enable bypass of the firewall/NAT boundary and exposure of internal LAN services to the public internet.
Title CVE-2026-75501
References

cve-icon MITRE

Status: PUBLISHED

Assigner: certcc

Published: 2026-08-21T14:47:04.279Z

Updated: 2026-08-25T19:26:53.449Z

Reserved: 2026-08-17T20:36:51.717Z

Link: CVE-2026-75501

cve-icon Vulnrichment

Updated: 2026-08-21T16:08:02.872Z

cve-icon NVD

Status : Received

Published: 2026-08-21T15:16:47.070

Modified: 2026-08-25T20:17:04.150

Link: CVE-2026-75501

cve-icon Redhat

No data.