Which versions of bumdlerl are malicious?

The following RubyGems versions of bumdlerl are flagged malicious: 1.0.0, 1.0.57234. Treat any of these as compromised.

How do I remediate bumdlerl if I installed it?

Remove bumdlerl 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 bumdlerl — how do I know if it already compromised me?

If bumdlerl 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 bumdlerl part of a known attack campaign?

Yes — bumdlerl is associated with the RLMA-2026-07535 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 bumdlerl across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for bumdlerl (2 malicious versions).

Malicious package

bumdlerlRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bumdlerl is a confirmed malicious RubyGems package (MAL-2026-16849) that executes malicious code on install (malicious versions 1.0.0, 1.0.57234). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bumdlerl (RubyGems)

MAL-2026-16849

Immediate action

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

gem uninstall bumdlerl

Malicious versions

2 flagged

1.0.01.0.57234

Indicators of compromise (SHA-256)

34483639685004e4190eca0febf2675198f193da5993ac797477d95a6bf5b366

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bumdlerl (2 malicious versions).
If you installed it — respond
Remove bumdlerl 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 bumdlerl 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. bumdlerl on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.57234 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07535

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bumdlerl-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

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