CVE-2025-30210

Bruno is an open source IDE for exploring and testing APIs. Prior to 1.39.1, the custom tool-tip components which internally use react-tooltip were setting the content (in this case the Environment name) as raw HTML which then gets injected into DOM on hover. This, combined with loose Content Security Policy restrictions, allowed any valid HTML text containing inline script to get executed on hovering over the respective Environments name. This vulnerabilitys attack surface is limited strictly to scenarios where users import collections from untrusted or malicious sources. The exploit requires deliberate action from the user—specifically, downloading and opening an externally provided malicious Bruno or Postman collection export and the user hovers on the environment name. This vulnerability is fixed in 1.39.1.

Weakness

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as “<”, “>”, and “&” that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.

Potential Mitigations

• Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
• The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/18.html
• https://cwe.mitre.org/data/definitions/193.html
• https://cwe.mitre.org/data/definitions/32.html
• https://cwe.mitre.org/data/definitions/86.html

References

• https://github.com/usebruno/bruno/security/advisories/GHSA-fqxc-cxph-9vq8