Which versions of browserslist-db are malicious?

The following npm versions of browserslist-db are flagged malicious: 99.1.0. Treat any of these as compromised.

How do I remediate browserslist-db if I installed it?

Remove browserslist-db from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed browserslist-db — how do I know if it already compromised me?

If browserslist-db was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

How do I find browserslist-db across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for browserslist-db (version 99.1.0).

Malicious package

browserslist-dbnpm

Advisory published May 1, 2026Updated May 12, 2026

browserslist-db is a confirmed malicious npm package (MAL-2026-3307) that executes malicious code on install (malicious version 99.1.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in browserslist-db (npm)

MAL-2026-3307

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall browserslist-db

What this malware does

The package browserslist-db was found to contain malicious code.

The OpenSSF Package Analysis project identified 'browserslist-db' @ 99.1.0 (npm) as malicious.

It is considered malicious because:

The package communicates with a domain associated with malicious activity.

Malicious versions

1 flagged

99.1.0

Indicators of compromise (SHA-256)

128651c0685d0b04a4fb2a0ec7f16eabd80be3ef038a3a745b02ea383dd863ff

f700f90f8bd70ca869ddaf27285327f5a926c28ac9d80cd5c8cad3ac25bb25ab

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for browserslist-db (version 99.1.0).
If you installed it — respond
Remove browserslist-db from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If browserslist-db was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. browserslist-db on npm has been identified as a malicious package (version 99.1.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Credits

Amazon Inspector · finder
OpenSSF: Package Analysis · finder

Detect & block this

O3 blocks browserslist-db-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database