CVE-2026-42994Known exploitationNetwork attack vector

Credential theft via malicious npm preinstall hook

Published May 1, 2026 · Updated May 1, 2026

Malicious code in Bitwarden CLI 2026.4.0 from npm allows remote attackers to steal host and development credentials during installation. The package's preinstall hook invokes bw_setup.js and bw1.js, which collect tokens, SSH material, environment files, shell history, and cloud secrets for exfiltration. Exposure requires installation from npm during the 93-minute publication window; other distribution paths were unaffected, and Bitwarden found no vault-data access.

CVSS severity8.8
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Malicious code in Bitwarden CLI 2026.4.0 from npm allows remote attackers to steal host and development credentials during installation. The package's preinstall hook invokes bw_setup.js and bw1.js, which collect tokens, SSH material, environment files, shell history, and cloud secrets for exfiltration. Exposure requires installation from npm during the 93-minute publication window; other distribution paths were unaffected, and Bitwarden found no vault-data access.

The record

CVE
CVE-2026-42994
Published
May 1, 2026
Updated
May 1, 2026
Vendor
Bitwarden
Product
Bitwarden CLI
Classifications
CWE-78, CWE-94, T1195.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 22, 2026Exploitation reportedMalicious npm distribution of Bitwarden CLI 2026.4.0
  2. May 1, 2026CVE publishedPublication date reported by the CVE source.
  3. May 1, 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=2026.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bitwarden · Bitwarden CLIversion=2026.4.0

Published CVSS scores

8.8MITRECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
9.8NVDCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1195.002Compromise Software Supply Chain

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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