CVE-2025-41086

Authorization bypass in GAMS from GAMS Development Corp.

Published Dec 2, 2025 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
Vulnerability in the access control system of the GAMS licensing system that allows unlimited valid licenses to be generated, bypassing any usage restrictions. The validator uses an insecure checksum algorithm; knowing this algorithm and the format of the license lines, an attacker can recalculate the checksum and generate a valid license to grant themselves full privileges without credentials or access to the source code, allowing them unrestricted access to GAMS's mathematical models and commercial solvers.

Remediation

Vendor Solution

The vulnerability has been fixed in GAMS version 51.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Gams gams
CPEs cpe:2.3:a:gams:access_control_system:*:*:*:*:*:*:*:* cpe:2.3:a:gams:gams:*:*:*:*:*:*:*:*
Vendors & Products Gams access Control System
Gams gams
Type Values Removed Values Added
First Time appeared Gams
Gams access Control System
CPEs cpe:2.3:a:gams:access_control_system:*:*:*:*:*:*:*:*
Vendors & Products Gams
Gams access Control System
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Vulnerability in the access control system of the GAMS licensing system that allows unlimited valid licenses to be generated, bypassing any usage restrictions. The validator uses an insecure checksum algorithm; knowing this algorithm and the format of the license lines, an attacker can recalculate the checksum and generate a valid license to grant themselves full privileges without credentials or access to the source code, allowing them unrestricted access to GAMS's mathematical models and commercial solvers.
Title Authorization bypass in GAMS from GAMS Development Corp.
First Time appeared Ams Development Corp.
Ams Development Corp. gams
Weaknesses CWE-639
CPEs cpe:2.3:a:ams_development_corp.:gams:*:*:*:*:*:*:*:*
Vendors & Products Ams Development Corp.
Ams Development Corp. gams
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
INCIBE
Published
Updated
Dec 2, 2025, 2:24 PM
Reserved
Apr 16, 2025, 9:09 AM
Status
Analyzed
Published
Dec 2, 2025, 2:16 PM
Modified
Oct 18, 2026, 6:10 PM