CVE-2026-34841Known exploitationNetwork attack vector

RAT installation via compromised package dependency

Published Apr 6, 2026 · Updated Apr 6, 2026

Malicious dependency execution in @usebruno/cli before 3.2.1 allows attackers to install a RAT through an npm install. A ranged axios dependency could resolve compromised axios 1.14.1 or 0.30.4, whose hidden dependency ran a malicious postinstall script. Exposure required a CLI installation from 00:21 to about 03:30 UTC on March 31, 2026; desktop users and other installation times were unaffected, and the RAT enabled credential and sensitive-data exfiltration.

CVSS severity9.8
Critical
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Malicious dependency execution in @usebruno/cli before 3.2.1 allows attackers to install a RAT through an npm install. A ranged axios dependency could resolve compromised axios 1.14.1 or 0.30.4, whose hidden dependency ran a malicious postinstall script. Exposure required a CLI installation from 00:21 to about 03:30 UTC on March 31, 2026; desktop users and other installation times were unaffected, and the RAT enabled credential and sensitive-data exfiltration.

The record

CVE
CVE-2026-34841
Published
Apr 6, 2026
Updated
Apr 6, 2026
Vendor
Bruno
Product
Bruno
Classifications
CWE-494, CWE-506, T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 31, 2026Exploitation reportedCompromised axios releases reached Bruno CLI installations
  2. Apr 6, 2026CVE publishedPublication date reported by the CVE source.
  3. Apr 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bruno · Brunoversion=< 3.2.1

Published CVSS scores

9.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-494Download of Code Without Integrity Check
CWE-506Embedded Malicious Code
T1195.001Compromise Software Dependencies and Development Tools

Public exploit references

No public exploit references are available in this record.

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Reported exploitation

Technologies

Your stack

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Your stack

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