Which versions of webpack-dev-server are malicious?

The following RubyGems versions of webpack-dev-server are flagged malicious: 9.1.0, 9.9.0, 9.9.1, 9.9.8, 9.9.9. Treat any of these as compromised.

How do I remediate webpack-dev-server if I installed it?

Remove webpack-dev-server 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 webpack-dev-server — how do I know if it already compromised me?

If webpack-dev-server 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.

Is webpack-dev-server part of a known attack campaign?

Yes — webpack-dev-server is associated with the RLMA-2025-03728, RLUA-2025-06637 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find webpack-dev-server across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for webpack-dev-server (5 malicious versions).

Malicious package

webpack-dev-serverRubyGems

Advisory published Jul 31, 2025Updated Jul 23, 2026

webpack-dev-server is a confirmed malicious RubyGems package (MAL-2025-6629) that executes malicious code on install (malicious versions 9.1.0, 9.9.0, 9.9.1…). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in webpack-dev-server (RubyGems)

MAL-2025-6629

Immediate action

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

gem uninstall webpack-dev-server

Malicious versions

5 flagged

9.1.09.9.09.9.19.9.89.9.9

Indicators of compromise (SHA-256)

37693c21dc7c3dba7a5767f4deb1dc336e25868bb633c96686748143f62f6ca7

133ba305d2fb881082e127c8ce556d8a695c4bdea5fdb8b8fb63626da365ab20

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for webpack-dev-server (5 malicious versions).
If you installed it — respond
Remove webpack-dev-server 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 webpack-dev-server 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. webpack-dev-server on RubyGems has been identified as a malicious package (versions 9.1.0, 9.9.0, 9.9.1, 9.9.8, 9.9.9 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-03728RLUA-2025-06637

References

intel.aikido.dev

Credits

ReversingLabs · finder

Detect & block this

O3 blocks webpack-dev-server-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

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