CVE-2026-34841

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 postinstall script
• 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 axios to 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:

1. Reinstall dependencies
2. 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

CVE-2026-34841 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.2.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-34841? CVE-2026-34841 is a critical-severity security vulnerability in @usebruno/cli (npm), affecting versions < 3.2.0. It is fixed in 3.2.1.
2. How severe is CVE-2026-34841? CVE-2026-34841 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of @usebruno/cli are affected by CVE-2026-34841? @usebruno/cli (npm) versions < 3.2.0 is affected.
4. Is there a fix for CVE-2026-34841? Yes. CVE-2026-34841 is fixed in 3.2.1. Upgrade to this version or later.
5. Is CVE-2026-34841 exploitable, and should I be worried? Whether CVE-2026-34841 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-34841 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-34841? Upgrade @usebruno/cli to 3.2.1 or later.