Authorization bypass in GAMS from GAMS Development Corp.
GAMS: 49.6.0 and earlier versions.
INCIBE has coordinated the publication of a medium-severity vulnerability affecting GAMS from GAMS Development Corp, a tool for creating mathematical models. The vulnerability was discovered by Francisco Guerrero Gallardo and Juan Embid Sánchez.
This vulnerability has been assigned the following code, CVSS v4.0 base score, CVSS vector, and CWE vulnerability type:
- CVE-2025-41086: CVSS v4.0: 6.9 | CVSS AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N | CWE-639
The vulnerability has been fixed in GAMS version 51.
CVE-2025-41086: 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.
