CVE-2025-41086Network attack vector

Unrestricted solver access via forgeable license checksums

Published Dec 2, 2025 · Updated Dec 2, 2025

Authorization bypass in affected GAMS releases allows remote attackers to forge licenses and gain unrestricted commercial-solver access. The licensing validator accepts a checksum produced by an insecure algorithm over attacker-controlled license-line data, allowing a forged line to pass as valid. No credentials or source-code access is required; knowledge of the checksum algorithm and license-line format is enough to remove usage restrictions.

CVSS severity6.9
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in affected GAMS releases allows remote attackers to forge licenses and gain unrestricted commercial-solver access. The licensing validator accepts a checksum produced by an insecure algorithm over attacker-controlled license-line data, allowing a forged line to pass as valid. No credentials or source-code access is required; knowledge of the checksum algorithm and license-line format is enough to remove usage restrictions.

The record

CVE
CVE-2025-41086
Published
Dec 2, 2025
Updated
Dec 2, 2025
Vendor
GAMS Development Corporation
Product
GAMS
Classifications
CWE-639
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=49.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GAMS Development Corporation · GAMSversion=0 <=49.6.0

Published CVSS scores

6.9INCIBE-CERTCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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