# CVE-2026-34841: Axios npm supply chain attack via @usebruno/cli

Source: https://junglewise.ai/threats/cve-2026-34841-axios-npm-supply-chain-attack-via-usebruno-cli  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-06. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-34841 · Severity: critical · CVSS 9.8 · Published 2026-04-06

@usebruno/cli is a command-line tool for the Bruno API testing platform. Between March 31 and April 1, 2026, users who ran npm install during a specific window received compromised versions of the axios dependency that deployed a remote access trojan (RAT). This allowed attackers to execute arbitrary code on developer machines, steal credentials and sensitive data, and maintain persistent access to affected systems.

Technologies: [Axios](https://junglewise.ai/threats/technologies/axios). Vendors: [Axios](https://junglewise.ai/threats/vendors/axios), [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-34841 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34841 being exploited in the wild.

**How severe is CVE-2026-34841?** Critical severity, with a CVSS score of 9.8, published 6 April 2026.

**Which products and versions are affected?** Axios 1.14.1, 0.30.4 (compromised); affected versions distributed through @usebruno/cli < 3.2.0; @usebruno/cli (npm) SEMVER:introduced=0,fixed=3.2.1.

**Is there a fix for CVE-2026-34841?** Yes. @usebruno/cli (npm): upgrade to 3.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-34841 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-34841?** Check whether you run Axios, @usebruno/cli (npm) or Usebruno Bruno at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @usebruno/cli (npm): upgrade to 3.2.1 or later

  ```sh
  npm install @usebruno/cli@3.2.1
  ```


## Technical details

This is a supply chain attack targeting the axios npm package through dependency injection. Compromised versions (1.14.1 and 0.30.4) introduced a malicious postinstall script that executed a cross-platform RAT. The attack affected @usebruno/cli users who ran npm install between 00:21 UTC and ~03:30 UTC on March 31, 2026. The vulnerability is classified as improper integrity checking of downloaded code (CWE-494) and embedded malicious code (CWE-506). No user interaction or privileges are required—the exploit occurs automatically during package installation. Patches involve removing compromised axios versions from npm and pinning @usebruno/cli to safe versions (3.2.1+).

## Affected products

- Bruno @usebruno/cli < 3.2.1
- Axios axios 1.14.1, 0.30.4 (compromised); affected versions distributed through @usebruno/cli < 3.2.0

## Identifiers

- CVE-2026-34841
- GHSA-658g-p7jg-wx5g

## Timeline

- 2026-03-31: exploited: Supply chain attack active between 00:21 UTC and ~03:30 UTC on March 31, 2026
- 2026-03-31: disclosed: Advisory published
- 2026-04-02: patched: @usebruno/cli version 3.2.1 released; compromised axios versions removed from npm

## References

- [https://github.com/usebruno/bruno/security/advisories/GHSA-658g-p7jg-wx5g](https://github.com/usebruno/bruno/security/advisories/GHSA-658g-p7jg-wx5g)

## Related threats

- [Axios NO_PROXY CIDR notation bypass in Node.js adapter](https://junglewise.ai/threats/cve-2026-101899-axios-cidr-form-no-proxy-entries-are-ignored-causing-proxy)
- [Axios prototype pollution in ToFormData](https://junglewise.ai/threats/cve-2026-101909-axios-is-a-promise-based-http-client-for-the-browser-and-node-js)
- [Axios fetch adapter header injection via prototype pollution](https://junglewise.ai/threats/cve-2026-101908-axios-is-a-promise-based-http-client-for-the-browser-and-node-js)
- [Axios fetch adapter maxRedirects bypass](https://junglewise.ai/threats/cve-2026-101907-axios-is-a-promise-based-http-client-for-the-browser-and-node-js)
- [Axios ReDoS in shouldBypassProxy regular expression](https://junglewise.ai/threats/cve-2026-101906-axios-is-a-promise-based-http-client-for-the-browser-and-node-js)