Vulnerability in Usebruno Bruno

CVE-2025-30354

Bruno is an open source IDE for exploring and testing APIs. A bug in the assertion runtime caused assert expressions to run in Developer Mode, even if Safe Mode was selected. The bug resulted in the sandbox settings to be ignored for the particular case where a single request is run/sent. This vulnerability's 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 collection. The vulnerability is fixed in 1.39.1.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (27.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-30354: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-30354?
CVE-2025-30354 is a medium-severity vulnerability in Usebruno Bruno, classified under Permissive Cross-domain Policy with Untrusted Domains. CVSS score: 4.3/10. Published 2025-04-01.
How severe is CVE-2025-30354?
Medium severity. CVSS v3 base score is 4.3 out of 10.