Vulnerability · Published Aug 17, 2026 · Assigned by GitHub_M
CVE-2025-27621UpTrain has a Constant Default API Key
High 7.7
In plain English
A high-severity improper authentication in uptrain from uptrain-ai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Official description
UpTrain is an open-source platform to evaluate and improve generative AI applications. In version 0.7.1 and prior, the UpTrain backend creates a new default user with a static username, where the username is also used as the default API key. The UpTrain backend also has an open CORS policy. Using these two primitives, any website can make a authenticated cross-origin request to the UpTrain instance by providing the default API key in the header `uptrain-access-token`. This issue may allow arbitrary websites to perform privileged operations on the UpTrain instance, as if they were the default logged in user. As of time of publication, no known patches are available.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| uptrain-ai | uptrain | <= 0.7.1 |
Weakness: CWE-287 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P