CVE-2026-34841 is a critical-severity (CVSS 9.8) CWE-494 vulnerability in @usebruno/cli. A fix is available for @usebruno/cli — see the affected versions and patch details below.
Axios npm Supply Chain Incident Impacting @usebruno/cli
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-34841.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@usebruno/clinpmDescription
Impact
This is a supply chain attack involving compromised versions of the axios npm package, which introduced a hidden dependency deploying a cross-platform Remote Access Trojan (RAT).
Users of @usebruno/cli who ran npm install between 00:21 UTC and ~03:30 UTC on March 31, 2026 may have been impacted.
Potential impact includes:
- Execution of a malicious
postinstallscript - Remote Access Trojan (RAT) installation
- Exfiltration of credentials and sensitive data
Not impacted:
- Bruno desktop app users
- Users who installed outside the attack window
Patches
The compromised axios versions (1.14.1, 0.30.4) have been removed from npm, and new installations will now resolve to safe versions.
Additionally, Bruno has taken further hardening steps:
- Pinned
axiosto a known safe version to prevent accidental resolution to malicious releases - Fix implemented in: https://github.com/usebruno/bruno/pull/7632
Recommendation
If users installed @usebruno/cli during the affected window:
- Reinstall dependencies
- Rotate all credentials and secrets:
For additional guidance on securing your system, refer to this article: https://www.aikido.dev/blog/axios-npm-compromised-maintainer-hijacked-rat
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @usebruno/cli | all versions | 3.2.1npm install @usebruno/cli@3.2.1 |
Affected Products
brunousebrunoDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @usebruno/cli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @usebruno/cli to 3.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34841 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-34841 in your dependencies?
Find it across npm, including transitive dependencies.