Authorization bypass in GAMS from GAMS Development Corp.
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-639.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| AMS Development Corp. | GAMS | up to 49.6.0 | — | No fix listed | CNA |
- GAMS VendorAMS Development Corp. Affected up to 49.6.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-41086
- 2026-10-03 Alias added: GHSA-ff5f-4h34-m3c8
References
Sources
- CVE-2025-41086 · CVE Program
- CVE-2025-41086 · NVD
- FIRST EPSS
- GHSA-ff5f-4h34-m3c8 · GitHub Advisory Database · CC BY 4.0
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